ARM: ux500: Reclassify PRCMU AUXDATA entry

We still need to utilise the AUXDATA system for the PRCMU to pass
through platform data which can not be DT:ed i.e. regulator initialisation
values. All we're doing in this patch is changing the comment header to be
more accurate.

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