ARM: dts: Fix cm2 and prm sizes for omap4

The size of these modules is 0x2000, not 0x3000. The extra 0x1000
after 0x2000 is for the interconnect target agent which is a separate
device.

Fixes: 7415b0b4 ("ARM: dts: omap4: add minimal l4 bus layout with
control module support")
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>