OMAP3 GPTIMER: fix GPTIMER12 IRQ

GPTIMER12 IRQ is at IRQ 95 on OMAP3, unlike OMAP2.  (ref: OMAP34xx
Multimedia High Security (HS) Device Silicon Revision 3.0 Security
Addendum Rev. B, SWPU119B)

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