x86/mm: Force-inline __phys_addr_nodebug()

Fix:

  vmlinux.o: warning: objtool: __sev_es_nmi_complete()+0x8b: call to __phys_addr_nodebug() leaves .noinstr.text section

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220324183607.31717-4-bp@alien8.de