ARM: dts: Use clock-output-names for dra7

With the TI clocks supporting the use of clock-output-names devicetree
property, we no longer need to use non-standard node names for clocks.

Depends-on: 31aa7056 ("ARM: dts: Don't use legacy clock defines for dra7 clkctrl")
Depends-on: 9206a3af ("clk: ti: Move dra7 clock devices out of the legacy section")
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Tero Kristo <kristo@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Message-Id: <20220204080842.40673-1-tony@atomide.com>