powerpc, 5xx: remove support for 5xx

There was for long time no activity in the 5xx area.
We need to go further and convert to Kconfig, but it
turned out, nobody is interested anymore in 5xx,
so remove it.

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/common/board_f.c b/common/board_f.c
index b02ca37..0a1ef1a 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -547,8 +547,7 @@
 	bd->bi_sramsize = CONFIG_SYS_SRAM_SIZE;		/* size  of SRAM */
 #endif
 
-#if defined(CONFIG_5xx) || \
-		defined(CONFIG_E500) || defined(CONFIG_MPC86xx)
+#if defined(CONFIG_E500) || defined(CONFIG_MPC86xx)
 	bd->bi_immr_base = CONFIG_SYS_IMMR;	/* base  of IMMR register     */
 #endif
 #if defined(CONFIG_MPC5xxx) || defined(CONFIG_M68K)