ppc/85xx: Introduce RESET_VECTOR_ADDRESS to handle non-standard link address

Some board ports place TEXT_BASE at a location that would cause the
RESET_VECTOR_ADDRESS not to be at 0xfffffffc when we link.  By default
we assume RESET_VECTOR_ADDRESS will be 0xfffffffc if the board doesn't
explicitly set it.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Wolfgang Denk <wd@denx.de>
diff --git a/config.mk b/config.mk
index 8852157..8cfd60c 100644
--- a/config.mk
+++ b/config.mk
@@ -128,6 +128,10 @@
 CPPFLAGS += -DTEXT_BASE=$(TEXT_BASE)
 endif
 
+ifneq ($(RESET_VECTOR_ADDRESS),)
+CPPFLAGS += -DRESET_VECTOR_ADDRESS=$(RESET_VECTOR_ADDRESS)
+endif
+
 ifneq ($(OBJTREE),$(SRCTREE))
 CPPFLAGS += -I$(OBJTREE)/include2 -I$(OBJTREE)/include
 endif