fbdev: s3c2410fb: remove mach header dependency

fbdev: s3c2410fb: remove mach header dependency

The s3c2410fb driver is too deeply intertwined with the s3c24xx
platform code. Change it in a way that avoids the use of platform
header files but having all interface data in a platform_data
header, and the private register definitions next to the driver
itself.

One ugly bit here is that the driver pokes directly into gpio
registers, which are owned by another driver. Passing the
mapped addresses in platform_data is somewhat suboptimal, but
it is a small improvement over the previous version.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200806182059.2431-33-krzk@kernel.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>