x86/rtc: Remove duplicate const specifier

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: Colin Ian King <colin.king@canonical.com>
Link: http://lkml.kernel.org/r/1421244475-313-1-git-send-email-colin.king@canonical.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>