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/nds32/lib/board.c b/arch/nds32/lib/board.c
index c919928..a7d27fc 100644
--- a/arch/nds32/lib/board.c
+++ b/arch/nds32/lib/board.c
@@ -192,7 +192,7 @@
 
 	memset((void *)gd, 0, GENERATED_GBL_DATA_SIZE);
 
-	gd->mon_len = (unsigned int)(&__bss_end__) - (unsigned int)(&_start);
+	gd->mon_len = (unsigned int)(&__bss_end) - (unsigned int)(&_start);
 
 	for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
 		if ((*init_fnc_ptr)() != 0)