ARM: dts: OMAP2: fix interrupt number for rng

The irq data for rng module defined in hwmod data previously
missed the OMAP_INTC_START relative offset, so the interrupt
number is probably misconfigured during the DT node addition
adjusting for this OMAP_INTC_START. Interrupt #36 is associated
with a watchdog timer, so fix the rng module's interrupt to the
appropriate interrupt #52.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>