powerpc: enable the relocatable support for the fsl booke 32bit kernel

This is based on the codes in the head_44x.S. The difference is that
the init tlb size we used is 64M. With this patch we can only load the
kernel at address between memstart_addr ~ memstart_addr + 64M. We will
fix this restriction in the following patches.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>

diff --cc arch/powerpc/Kconfig
Simple merge

diff --cc arch/powerpc/kernel/fsl_booke_entry_mapping.S
Simple merge

diff --cc arch/powerpc/kernel/head_fsl_booke.S
Simple merge

diff --cc arch/powerpc/mm/fsl_booke_mmu.c
Simple merge