powerpc/32: Split kexec low level code out of misc_32.S

Almost half of misc_32.S is dedicated to kexec.
That's the relocation function for kexec.

Drop it into a dedicated kexec_relocate_32.S
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e235973a1198195763afd3b6baffa548a83f4611.1572351221.git.christophe.leroy@c-s.fr

arch/powerpc/kernel/Makefile

@@ -82,6 +82,7 @@ obj-$(CONFIG_FA_DUMP)		+= fadump.o
 obj-$(CONFIG_PRESERVE_FA_DUMP)	+= fadump.o
 ifdef CONFIG_PPC32
 obj-$(CONFIG_E500)		+= idle_e500.o
+obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate_32.o
 endif
 obj-$(CONFIG_PPC_BOOK3S_32)	+= idle_6xx.o l2cr_6xx.o cpu_setup_6xx.o
 obj-$(CONFIG_TAU)		+= tau_6xx.o