x86/alternatives: Move apply_relocation() out of init section

This function is now called from a few places that are no __init_or_module,
resulting a link time warning:

  WARNING: modpost: vmlinux: section mismatch in reference: patch_dest+0x8a (section: .text) -> apply_relocation (section: .init.text)

Remove the annotation here.

[ mingo: Also sync up add_nop() with these changes. ]

Fixes: 17bce3b2 ("x86/callthunks: Handle %rip-relative relocations in call thunk template")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Uros Bizjak <ubizjak@gmail.com>
Link: https://lore.kernel.org/r/20231204072856.1033621-1-arnd@kernel.org