sh: intc - add support for SH7705

This patch converts the cpu specific interrupt setup code for
sh7705 from ipr to intc. While at it new vectors are added to
match the information provided by the datasheet.

Vectors for IRQ4 and IRQ5 are enabled by default.

Use plat_irq_setup_pins() if pins IRQ0-3 should be used in IRQ mode.

This patch also adds sh7705 specific platform data for the rtc driver.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>