mips/kvm: Cleanup .push/.pop directives in kvm_locore.S

There are:
	.set	push
	.set	noreorder
	.set	noat
	 .
	 .
	 .
	.set	pop

Sequences all over the place in this file, but in some places the
final ".set pop" is erroneously converted to ".set push", so none of
these really do what they appear to.

Clean up the whole mess by moving ".set noreorder", ".set noat" to the
top, and get rid of everything else.

Generated object code is unchanged.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>