mfd: dbx500-prcmu: Correctly reorder PRCMU clock identifiers

... as stipulated by the Hardware Specification document.

Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>