x86/mm: Remove Xen-PV leftovers from init_32.c

There are still some unneeded paravirt calls in arch/x86/mm/init_32.c.

Remove them.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230609055100.12633-1-jgross@suse.com