ARM: shmobile: koelsch-reference: Work around core clock issues

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, i2c2, msiof0, qspi_mod, and
thermal. More clocks can be added if needed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>