sh: Build drivers/sh for ARM-based SH-Mobile CPUs.

Build drivers/sh in the case of ARM-based SH-Mobile CPUs.
Shared code for the interrupt controller (INTC) and
the gpio/pinmux (PFC) is located there.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>