rtc: ia64: allow other architectures to use EFI RTC

Currently, the rtc-efi driver is restricted to ia64 only.  Newer
architectures with EFI support may want to also use that driver.  This
patch moves the platform device setup from ia64 into drivers/rtc and
allow any architecture with CONFIG_EFI=y to use the rtc-efi driver.

Signed-off-by: Mark Salter <msalter@redhat.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>