Revert "Avoid initrd and logbuffer area overlaps"

This reverts commit 1b5605ca57fbb364f4d78eeee28b974ed875e888
which breaks building on all PPC boards that don't use a log buffer.
diff --git a/common/cmd_log.c b/common/cmd_log.c
index 8e04941..b9f9ba0 100644
--- a/common/cmd_log.c
+++ b/common/cmd_log.c
@@ -66,12 +66,6 @@
 #endif
 static char *lbuf;
 
-unsigned long __logbuffer_base(void)
-{
-	return CFG_SDRAM_BASE + gd->bd->bi_memsize - LOGBUFF_LEN;
-}
-unsigned long logbuffer_base (void) __attribute__((weak, alias("__logbuffer_base")));
-
 void logbuff_init_ptrs (void)
 {
 	unsigned long tag, post_word;
@@ -81,7 +75,7 @@
 	log = (logbuff_t *)CONFIG_ALT_LH_ADDR;
 	lbuf = (char *)CONFIG_ALT_LB_ADDR;
 #else
-	log = (logbuff_t *)(logbuffer_base ()) - 1;
+	log = (logbuff_t *)(gd->bd->bi_memsize-LOGBUFF_LEN) - 1;
 	lbuf = (char *)log->buf;
 #endif