x86/rtc: Remove duplicate const specifier

Building with clang:

  CC      arch/x86/kernel/rtc.o
arch/x86/kernel/rtc.c:173:29: warning: duplicate 'const' declaration
  specifier [-Wduplicate-decl-specifier]
        static const char * const  const ids[] __initconst =

Remove the duplicate const, it is not needed and causes a warning.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Link: http://lkml.kernel.org/r/1421244475-313-1-git-send-email-colin.king@canonical.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/rtc.c

@@ -170,7 +170,7 @@ static struct platform_device rtc_device = {
 static __init int add_rtc_cmos(void)
 {
 #ifdef CONFIG_PNP
-	static const char * const  const ids[] __initconst =
+	static const char * const ids[] __initconst =
 	    { "PNP0b00", "PNP0b01", "PNP0b02", };
 	struct pnp_dev *dev;
 	struct pnp_id *id;