powerpc: Curb objtool unannotated intra-function call warnings

objtool throws the following unannotated intra-function call warnings:
arch/powerpc/kernel/entry_64.o: warning: objtool: .text+0x4: unannotated intra-function call
arch/powerpc/kvm/book3s_hv_rmhandlers.o: warning: objtool: .text+0xe64: unannotated intra-function call
arch/powerpc/kvm/book3s_hv_rmhandlers.o: warning: objtool: .text+0xee4: unannotated intra-function call

Fix these warnings by annotating intra-function calls, using
ANNOTATE_INTRA_FUNCTION_CALL macro, to indicate that the branch targets
are valid.

Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221114175754.1131267-5-sv@linux.ibm.com