hw/tpm: Only build tpm_ppi.o if any of TPM_TIS/TPM_CRB is built

The TPM Physical Presence Interface routines are only used
by the CRB/TIS interfaces. Do not compile this file if any
of them is built.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>

hw/tpm/Makefile.objs

@@ -1,5 +1,5 @@
-common-obj-y += tpm_util.o
-obj-y += tpm_ppi.o
+common-obj-$(CONFIG_TPM) += tpm_util.o
+obj-$(call lor,$(CONFIG_TPM_TIS),$(CONFIG_TPM_CRB)) += tpm_ppi.o
 common-obj-$(CONFIG_TPM_TIS) += tpm_tis.o
 common-obj-$(CONFIG_TPM_CRB) += tpm_crb.o
 common-obj-$(CONFIG_TPM_PASSTHROUGH) += tpm_passthrough.o