ARM: s3c: Drop config symbol S3C24XX_PWM

ARM: s3c: Drop config symbol S3C24XX_PWM

The only effect of this symbol is to select PWM_SAMSUNG. Drop it and fix
the affected defconfigs to still keep PWM_SAMSUNG=y. Developers using
MACH_NEO1973_GTA02 and/or MACH_RX1950 now have to manually select PWM and
PWM_SAMSUNG (and get the freedom to select is as a module or not at all).
A side effect of this change is that allmodconfig now contains
PWM_SAMSUNG=m (which was =y before).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220328082638.112185-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>