Replace __bss_end__ with __bss_end

Note this is a tree-wide change affecting multiple architectures.

At present we use __bss_start, but mostly __bss_end__. This seems
inconsistent and in a number of places __bss_end is used instead.

Change to use __bss_end for the BSS end symbol throughout U-Boot. This
makes it possible to use the asm-generic/sections.h file on all
archs.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/powerpc/cpu/mpc5xxx/spl_boot.c b/arch/powerpc/cpu/mpc5xxx/spl_boot.c
index 080bd58..35611cc 100644
--- a/arch/powerpc/cpu/mpc5xxx/spl_boot.c
+++ b/arch/powerpc/cpu/mpc5xxx/spl_boot.c
@@ -76,7 +76,7 @@
 	initdram(0);
 
 	/* Clear bss */
-	memset(__bss_start, '\0', __bss_end__ - __bss_start);
+	memset(__bss_start, '\0', __bss_end - __bss_start);
 
 	/*
 	 * Call board_init_r() (SPL framework version) to load and boot