KVM: PPC: Book3S HV: kvmppc_hv_entry: remove .global scope

kvmppc_hv_entry isn't called from anywhere other than
book3s_hv_rmhandlers.S itself. Remove .global scope for this function
and annotate it with SYM_CODE_START_LOCAL and SYM_CODE_END.

Signed-off-by: Kautuk Consul <kconsul@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230327113320.3407491-1-kconsul@linux.vnet.ibm.com