arm64: dts: rockchip: Prepare RK3588 SoC dtsi files for per-variant OPPs

Rename the Rockchip RK3588 SoC dtsi files and, consequently, adjust their
contents appropriately, to prepare them for the ability to specify different
CPU and GPU OPPs for each of the supported RK3588 SoC variants.

As already discussed, [1][2][3][4] some of the RK3588 SoC variants require
different OPPs, and it makes more sense to have the OPPs already defined when
a board dts(i) file includes one of the SoC variant dtsi files (rk3588.dtsi,
rk3588j.dtsi or rk3588s.dtsi), rather than requiring the board dts(i) file
to also include a separate rk3588*-opp.dtsi file.  The choice of the SoC
variant is already made by the inclusion of the SoC dtsi file into the board
dts(i) file, and it doesn't make much sense to, effectively, allow the board
dts(i) file to include and use an incompatible set of OPPs for the already
selected RK3588 SoC variant.

The new naming scheme for the RK3588 SoC dtsi files uses "-base" and "-extra"
suffixes to denote the DT data shared between all RK5588 SoC variants, and
the DT data shared between the unrestricted SoC variants, respectively.
For example, the DT data for the RK3588 includes both rk3588-base.dtsi and
rk3588-extra.dtsi, because it's an unrestricted SoC variant, while the DT
data for the RK3588S variant includes rk3588-base.dtsi only, because it's
a restricted SoC variant, feature- and interface-wise.  This achieves a more
logical naming of the RK3588 SoC dtsi files, which reflects the way DT data
for the SoC variants is built by "stacking" the SoC variant features made
available through the "-base" and "-extra" SoC dtsi files.  Additionally,
the SoC variant dtsi files (rk3588.dtsi, rk3588j.dtsi and rk3588s.dtsi) are
no longer parents to any other SoC variant dtsi files, which should help with
making the new "stacking" approach cleaner and easier to follow.

The RK3588 pinctrl dtsi files are also renamed in the same way, for the sake
of consistency.  This also keeps the "-base" and "-extra" groups of the dtsi
files together when looked at in a directory listing, which is helpful.

The per-SoC-variant OPPs should go directly into the SoC dtsi files, if no
more than one SoC variant uses those OPPs, or be put into a separate "-opp"
dtsi file that's shared between and included from two or more SoC variant
dtsi files.  An example for the former is the non-shared OPP data that should
go directly into the RK3588J SoC variant dtsi file (i.e. rk3588j.dtsi), and
an example for the latter is the shared OPP data that should be put into
rk3588-opp.dtsi and be included from the RK3588 and RK3588S SoC variant dtsi
files (i.e. rk3588.dtsi and rk3588s.dtsi, respectively).  Consequently, if
the OPPs for the RK3588 and RK3588S SoC variants are ever made different,
the shared rk3588-opp.dtsi file should be deleted and the new OPPs should
be put directly into rk3588.dtsi and rk3588s.dtsi. [4]

No functional changes are introduced, which was validated by decompiling and
comparing all affected dtb files before and after these changes.

As a side note, due to the nature of introduced changes, this commit is best
viewed using the --break-rewrites option for git-log(1).

[1] https://lore.kernel.org/linux-rockchip/646a33e0-5c1b-471c-8183-2c0df40ea51a@cherry.de/
[2] https://lore.kernel.org/linux-rockchip/CABjd4Yxi=+3gkNnH3BysUzzYsji-=-yROtzEc8jM_g0roKB0-w@mail.gmail.com/
[3] https://lore.kernel.org/linux-rockchip/035a274be262528012173d463e25b55f@manjaro.org/
[4] https://lore.kernel.org/linux-rockchip/673dcf47596e7bc8ba065034e339bb1bbf9cdcb0.1716948159.git.dsimic@manjaro.org/T/#uSigned-off-by: Dragan Simic <dsimic@manjaro.org>
Link: https://lore.kernel.org/r/9ffedc0e2ca7f167d9d795b2a8f43cb9f56a653b.1717923308.git.dsimic@manjaro.orgSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3588j.dtsi

@@ -4,4 +4,4 @@
  *
  */
 
-#include "rk3588.dtsi"
+#include "rk3588-extra.dtsi"