Due to issues with runtime PM clock management, clocks not explicitly
managed by their drivers may not be enabled at all, or be inadvertently
disabled by the clk_disable_unused() late initcall.

Until this is fixed, add a temporary workaround, calling
shmobile_clk_workaround() with enable == true.

For now this enables the clocks for: ether, msiof1, qspi_mod, and
thermal. More clocks can be added if needed.

Based on work for the koelsch board by Geert Uytterhoeven.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>