x86/init: Make get/set_rtc_noop() public

Make get/set_rtc_noop() to be public so that they can be used
in other modules as well.

Co-developed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/1681192532-15460-2-git-send-email-ssengar@linux.microsoft.com


Signed-off-by: Wei Liu <wei.liu@kernel.org>