powerpc/kvm/booke: Fix altivec related build break

powerpc/kvm/booke: Fix altivec related build break

BugLink: http://bugs.launchpad.net/bugs/1794889
[ Upstream commit b2d7ecbe355698010a6b7a15eb179e09eb3d6a34 ]

Add missing "altivec unavailable" interrupt injection helper
thus fixing the linker error below:

  arch/powerpc/kvm/emulate_loadstore.o: In function `kvmppc_check_altivec_disabled':
  arch/powerpc/kvm/emulate_loadstore.c: undefined reference to `.kvmppc_core_queue_vec_unavail'

Fixes: 09f984961c137c4b ("KVM: PPC: Book3S: Add MMIO emulation for VMX instructions")
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>