ARM: OMAP: irqs: Fix NR_IRQS value to handle PRCM interrupts

The following commit: 2f31b516
Author: Tero Kristo <t-kristo@ti.com>
Date:   Fri Dec 16 14:37:00 2011 -0700

    ARM: OMAP4: PRM: use PRCM interrupt handler

introduced the PRCM interrupt handler and thus the need
for 64 more interrupts. Since SPARSE_IRQ is still not fully
functional on OMAP, the NR_IRQS needs to be updated to avoid
the failure that happen during irq_alloc_descs call inside
the PRCM driver:

[    0.208221] PRCM: failed to allocate irq descs: -12

Later the mux framework is then unable to request an IRQ from
the PRCM interrupt handler.

[    1.802795] mux: Failed to setup hwmod io irq -22

Fix that by adding 64 more interrupts for OMAP2PLUS config.

Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>