ARM: s3c: Avoid naming clash of S3C24xx and S3C64xx timer setup

PWM timer initialization has two independent implementations - one for
S3C24xx and one for S3C64xx. The naming however was always the same
and before also the declaration was shared. This is confusing, error
prone and might cause issues when trying to build multiplatform kernel.

Suggested-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200820204203.22328-1-krzk@kernel.org

ARM: s3c: move into a common directory

s3c24xx and s3c64xx have a lot in common, but are split across three
separate directories, which makes the interaction of the header files
more complicated than necessary.

Move all three directories into a new mach-s3c, with a minimal
set of changes to each file.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[krzk: Rebase, add s3c24xx and s3c64xx suffix to several files, add SPDX
headers to new files, remove plat-samsung from MAINTAINERS]
Co-developed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
https://lore.kernel.org/r/20200806182059.2431-39-krzk@kernel.org