efirtc: remove unnecessary code efi_rtc_open & efi_rtc_close

There is no advantage to keep 'struct file_operations.open & .close'
API's. So removed the unnecessary code efi_rtc_open & efi_rtc_close.

Signed-off-by: Naveen Kumar Parna <parna.naveenkumar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>