xen: delete new instances of added __cpuinit

xen: delete new instances of added __cpuinit

commit feb4056032864828c0db1dee6703412c31f5907c
("xen: Support 64-bit PV guest receiving NMIs") and
commit 4e9e1d62c3c3adf7c6e1d03a9b82c8ee5eddb0fa
( "xen/balloon: set a mapping for ballooned out pages")
added new instances of __cpuinit usage.

We removed this a couple versions ago; we now want to remove
the compat no-op stubs.  Introducing new users is not what
we want to see at this point in time, as it will break once
the stubs are gone.

Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>