powerpc: Build fix for powerpc KVM

Fix build failure for powerpc KVM by adding missing VPN_SHIFT definition
and the ';'

arch/powerpc/kvm/book3s_32_mmu_host.c: In function 'kvmppc_mmu_map_page':
arch/powerpc/kvm/book3s_32_mmu_host.c:176: error: 'VPN_SHIFT' undeclared (first use in this function)
arch/powerpc/kvm/book3s_32_mmu_host.c:176: error: (Each undeclared identifier is reported only once
arch/powerpc/kvm/book3s_32_mmu_host.c:176: error: for each function it appears in.)
arch/powerpc/kvm/book3s_32_mmu_host.c:178: error: expected ';' before 'next_pteg'
arch/powerpc/kvm/book3s_32_mmu_host.c:190: error: label 'next_pteg' used but not defined
make[1]: *** [arch/powerpc/kvm/book3s_32_mmu_host.o] Error 1

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>