MIPS: Simplify the weak annotation with __weak

Found by

$ find arch/mips/ -name "*.c" | xargs -i grep -H weak {} | grep -v __weak

[Ralf: Made this bulletproof by including <linux/compiler.h>]

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/874/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/boot/compressed/dbg.c

@@ -5,11 +5,11 @@
  * please select SYS_SUPPORTS_ZBOOT_UART16550 for your machine. othewise, you
  * need to implement your own putc().
  */
-
+#include <linux/compiler.h>
 #include <linux/init.h>
 #include <linux/types.h>
 
-void __attribute__ ((weak)) putc(char c)
+void __weak putc(char c)
 {
 }