MIPS: Make VPE count to be one-based.

When dealing with multiple VPEs, the count needs to be one-based
for correct initialization of the GIC.
Signed-off-by: NSteven J. Hill <sjhill@mips.com>

arch/mips/kernel/irq-gic.c

@@ -312,6 +312,7 @@ void __init gic_init(unsigned long gic_base_addr,
 
 	numvpes = (gicconfig & GIC_SH_CONFIG_NUMVPES_MSK) >>
 		  GIC_SH_CONFIG_NUMVPES_SHF;
+	numvpes = numvpes + 1;
 
 	gic_basic_init(numintrs, numvpes, intr_map, intr_map_size);