x86, efi: Convert efi_phys_get_time() args to physical addresses

Because callers of efi_phys_get_time() pass virtual stack
addresses as arguments, we need to find their corresponding
physical addresses and when calling GetTime() in physical mode.

Without this patch the following line is printed on boot,

	"Oops: efitime: can't read time!"

Signed-off-by: Maurice Ma <maurice.ma@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1318330333-4617-1-git-send-email-matt@console-pimps.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/platform/efi/efi.c

@@ -238,7 +238,8 @@ static efi_status_t __init phys_efi_get_time(efi_time_t *tm,
 
 	spin_lock_irqsave(&rtc_lock, flags);
 	efi_call_phys_prelog();
-	status = efi_call_phys2(efi_phys.get_time, tm, tc);
+	status = efi_call_phys2(efi_phys.get_time, virt_to_phys(tm),
+				virt_to_phys(tc));
 	efi_call_phys_epilog();
 	spin_unlock_irqrestore(&rtc_lock, flags);
 	return status;