ARM: OMAP2: Fix sparse, checkpatch warnings in OMAP2/3 IRQ code

Fix sparse warnings in mach-omap2/irq.c. Fix by defining
intc_bank_write_reg() and intc_bank_read_reg(), and convert INTC module
register access to use them rather than __raw_{read,write}l.

Also clear up some checkpatch warnings involving includes from asm/
rather than linux/.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>