efi_set_rtc_mmss() is never used to set RTC due to bugs found
on many EFI platforms. It is set directly by mach_set_rtc_mmss().
Hence, remove unused efi_set_rtc_mmss() function.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>