ppc: Enable full relocation to RAM

The following changes allow U-Boot to fully relocate from flash to
RAM:
 - Remove linker scripts' .fixup sections from the .text section
 - Add -mrelocatable to PLATFORM_RELFLAGS for all boards
 - Define CONFIG_RELOC_FIXUP_WORKS for all boards

Previously, U-Boot would partially relocate, but statically initialized
pointers needed to be manually relocated.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/lib_ppc/config.mk b/lib_ppc/config.mk
index 010d874..06a3b10 100644
--- a/lib_ppc/config.mk
+++ b/lib_ppc/config.mk
@@ -25,6 +25,7 @@
 
 STANDALONE_LOAD_ADDR = 0x40000
 
+PLATFORM_RELFLAGS += -mrelocatable
 PLATFORM_CPPFLAGS += -DCONFIG_PPC -D__powerpc__
 PLATFORM_LDFLAGS  += -n