ARM: ux500: Increase the size of the PRCMU's TCPM size

The Tightly Coupled Program Memory location is actually 32kB in
size, rather than the originally depicted 4kB.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>