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/lib/board.c b/arch/powerpc/lib/board.c
index 12270a4..0b23d30 100644
--- a/arch/powerpc/lib/board.c
+++ b/arch/powerpc/lib/board.c
@@ -123,7 +123,7 @@
 #endif
 
 extern ulong __init_end;
-extern ulong __bss_end__;
+extern ulong __bss_end;
 ulong monitor_flash_len;
 
 #if defined(CONFIG_CMD_BEDBUG)
@@ -419,7 +419,7 @@
 	 *  - monitor code
 	 *  - board info struct
 	 */
-	len = (ulong)&__bss_end__ - CONFIG_SYS_MONITOR_BASE;
+	len = (ulong)&__bss_end - CONFIG_SYS_MONITOR_BASE;
 
 	/*
 	 * Subtract specified amount of memory to hide so that it won't