powerpc/85xx: Add lbc suspend support for PM

Power supply for LBC registers is off when system go to deep-sleep state.
We save the values of registers before suspend and restore to registers
after resume.

We removed the last two reservation arrays from struct fsl_lbc_regs for
allocating less memory and minimizing the memcpy size.

Signed-off-by: Jiang Yutang <b14898@freescale.com>
Signed-off-by: Jia Hongtao <B38951@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>