powerpc/mpc85xx/p1_p2_rdb_pc: new SPL support

Introduces CONFIG_SPL_RELOC_TEXT_BASE and CONFIG_SPL_RELOC_STACK.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Andy Fleming <afleming@freescale.com>
diff --git a/README b/README
index ca2d10f..44cd65a 100644
--- a/README
+++ b/README
@@ -2653,6 +2653,10 @@
 		CONFIG_SPL_TEXT_BASE
 		TEXT_BASE for linking the SPL binary.
 
+		CONFIG_SPL_RELOC_TEXT_BASE
+		Address to relocate to.  If unspecified, this is equal to
+		CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
+
 		CONFIG_SPL_BSS_START_ADDR
 		Link address for the BSS within the SPL binary.
 
@@ -2662,6 +2666,11 @@
 		CONFIG_SPL_STACK
 		Adress of the start of the stack SPL will use
 
+		CONFIG_SPL_RELOC_STACK
+		Adress of the start of the stack SPL will use after
+		relocation.  If unspecified, this is equal to
+		CONFIG_SPL_STACK.
+
 		CONFIG_SYS_SPL_MALLOC_START
 		Starting address of the malloc pool used in SPL.