Revert "common/board_f: add setup of initial stack frame for MIPS"

Daniel discovered a better solution to the problem this was solving, so
don't do what this patch was doing anymore.

This reverts commit 666ba8444e81c3785a427ae6922e2feededab9a3.

Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/common/board_f.c b/common/board_f.c
index f8fd324..98c9c72 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -581,7 +581,7 @@
 	gd->irq_sp = gd->start_addr_sp;
 # endif
 #else
-# if defined(CONFIG_PPC) || defined(CONFIG_MIPS)
+# ifdef CONFIG_PPC
 	ulong *s;
 # endif
 
@@ -611,12 +611,6 @@
 	s = (ulong *) gd->start_addr_sp;
 	*s = 0; /* Terminate back chain */
 	*++s = 0; /* NULL return address */
-# elif defined(CONFIG_MIPS)
-	/* Clear initial stack frame */
-	s = (ulong *) gd->start_addr_sp;
-	*s-- = 0;
-	*s-- = 0;
-	gd->start_addr_sp = (ulong) s;
 # endif /* Architecture specific code */
 
 	return 0;