powerpc/32/kdump: Implement crash_setup_regs() using ppc_save_regs()

This replaces the dummy crash_setup_regs function with full-fledged
crash_setup_regs implementation.  On PPC32 we simply use the new
ppc_save_regs function to dump the registers.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/Makefile

@@ -102,7 +102,7 @@ endif
 
 obj-$(CONFIG_PPC64)		+= $(obj64-y)
 
-ifneq ($(CONFIG_XMON),)
+ifneq ($(CONFIG_XMON)$(CONFIG_KEXEC),)
 obj-y				+= ppc_save_regs.o
 endif