ARM: davinci: da8xx: fix interrupt handling

CP_INTC code in entry-macro.S code reads SECR1n register to see if
an interrupt was indeed pending. This register is actually marked as
write-only in the OMAP-L138 TRM. Moreover, the code just checks to see
the entire register is non-zero and does not check a specific interrupt
number.

Fix this to use interrupt pending bit in GIPR register for this purpose.
GIPR register is already being read to know the highest priority interrupt
pending.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>

arch/arm/mach-davinci/include/mach/entry-macro.S

@@ -30,12 +30,10 @@
 #endif
 #if defined(CONFIG_CP_INTC)
 1001:		ldr \irqnr, [\base, #0x80] /* get irq number */
+		mov \tmp, \irqnr, lsr #31
 		and \irqnr, \irqnr, #0xff  /* irq is in bits 0-9 */
-		mov \tmp, \irqnr, lsr #3
-		and \tmp, \tmp, #0xfc
-		add \tmp, \tmp, #0x280 /* get the register offset */
-		ldr \irqstat, [\base, \tmp] /* get the intc status */
-		cmp \irqstat, #0x0
+		and \tmp, \tmp, #0x1
+		cmp \tmp, #0x1
 #endif
 1002:
 		.endm