ARM: uniphier: move PLLCTRL register macros to each SoC .c file

ARM: uniphier: move PLLCTRL register macros to each SoC .c file

The new SoC PXs3 changed the address of PLL, but still uses the
same PLL name.  We can not define SC_*PLLCTRL in the common header.
Move them to per-SoC .c file.  Also, fix some PLL comments.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>