i386: Fix multiple definitions of __show_boot_progress

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/board/sc520_cdp/sc520_cdp_asm.S b/board/sc520_cdp/sc520_cdp_asm.S
index be7b2bb..7f70d65 100644
--- a/board/sc520_cdp/sc520_cdp_asm.S
+++ b/board/sc520_cdp/sc520_cdp_asm.S
@@ -76,8 +76,8 @@
 	jmp 	*%ebp		     /* return to caller */
 
 
-.globl __show_boot_progress
-__show_boot_progress:
+.globl show_boot_progress
+show_boot_progress:
 	out	%al, $0x80
 	xchg	%al, %ah
 	movw	$0x680, %dx