soc: renesas: Move pm-rcar to drivers/soc/renesas/rcar-sysc

Move the pm-rcar driver from arch/arm/mach-shmobile/ to
drivers/soc/renesas/, and its header file to include/linux/soc/renesas/,
so it can be shared between arm32 (R-Car H1 and Gen2) and arm64 (R-Car
Gen3). Rename it to rcar-sysc as it's really a driver for the R-Car
System Controller (SYSC).

Kill the intermediate PM_RCAR config symbol, as it's not user
configurable anymore, and to prepare for SoC-specific make rules.

Add the missing #include <linux/types.h> to rcar-sysc.h, which was
exposed by different include order.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>