ARM: mach-shmobile: fix cpu_base of gic_init() on sh73a0

The latest rmobile-latest doesn't run on ag5evm because of a
small mistake on initialization.
Though, I don't have any idea to write them smart.
anyway,

On sh73a0, GIC cpu_base is 0xf0000100 but 0xf0001000.

Signed-off-by: Takashi YOSHII <takashi.yoshii.zj@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>