ARM: s3c24xx: make S3C24XX_MISCCR access indirect

The clk driver uses both a function call into an exported
platform file and a direct register access to a hardcoded
virtual address for accessing the MISCCR register, both
become are a problem for a multiplatform kernel because
of the header file dependency.

Make this an indirect function call through platform data
instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20200806182059.2431-5-krzk@kernel.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>