sh: intc - rework core code

This patch reworks the intc core, implementing the following features:

- Support dual priority registers - one set and one clear register
- All 8/16/32 bit register combinations are now supported
- Both single mask and single enable bitmap register are supported
- Add code to set interrupt priority
- Speedup sense and priority configuration code
- Allocate data using bootmem, allows intc data structures to be
  __initdata
- Save memory - allocated memory footprint is smaller than intc
  structures

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

arch/sh/cchips/voyagergx/irq.c

@@ -50,7 +50,7 @@ static struct intc_vect vectors[] = {
 };
 
 static struct intc_mask_reg mask_registers[] = {
-	{ VOYAGER_INT_MASK, 1, 32, /* "Interrupt Mask", MMIO_base + 0x30 */
+	{ VOYAGER_INT_MASK, 0, 32, /* "Interrupt Mask", MMIO_base + 0x30 */
 	  { UP, G54, G53, G52, G51, G50, G49, G48,
 	    I2C, PW, 0, DMA, PCI, I2S, AC, US,
 	    0, 0, U1, U0, CV, MC, S1, S0,