Makefile: fix annoying sunxi hack message

every compilation shows this error

 Hack for sunxi which doesn't have a proper binman definition for
 64-bit boards

not only for sunxi-boards/arm64

fix this by changing to real comments

Fixes: 9f55ee259d0c ("Makefile: sunxi: Don't use binman to build ATF image")
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
diff --git a/Makefile b/Makefile
index 5fb68bf..d9a0881 100644
--- a/Makefile
+++ b/Makefile
@@ -1024,8 +1024,8 @@
 inputs: $(INPUTS-y)
 
 all: .binman_stamp inputs
-	# Hack for sunxi which doesn't have a proper binman definition for
-	# 64-bit boards
+# Hack for sunxi which doesn't have a proper binman definition for
+# 64-bit boards
 ifneq ($(CONFIG_ARCH_SUNXI)$(CONFIG_ARM64),yy)
 ifeq ($(CONFIG_BINMAN),y)
 	$(call if_changed,binman)