feat(tc): allow TARGET_VERSION=4

Add basic support for TARGET_VERSION=4. It extends the existing 'if'
statements in the Makefile and the header to allow them to take the
value of 4 and also specifies the SCMI platform info to use for TC4.

Change-Id: I8d8257671314277a133e88ef65fae8fada93d00e
Signed-off-by: Jackson Cooper-Driver <jackson.cooper-driver@arm.com>
Signed-off-by: Leo Yan <leo.yan@arm.com>
diff --git a/plat/arm/board/tc/tc_bl31_setup.c b/plat/arm/board/tc/tc_bl31_setup.c
index 53404df..801872a 100644
--- a/plat/arm/board/tc/tc_bl31_setup.c
+++ b/plat/arm/board/tc/tc_bl31_setup.c
@@ -58,7 +58,7 @@
 	.db_modify_mask = 0x1,
 	.ring_doorbell = &mhuv2_ring_doorbell,
 };
-#elif TARGET_PLATFORM == 3
+#elif TARGET_PLATFORM >= 3
 static scmi_channel_plat_info_t tc_scmi_plat_info = {
 	.scmi_mbx_mem = CSS_SCMI_PAYLOAD_BASE,
 	.db_reg_addr = PLAT_CSS_MHU_BASE + MHU_V3_SENDER_REG_SET(0),
@@ -66,7 +66,9 @@
 	.db_modify_mask = 0x1,
 	.ring_doorbell = &mhu_ring_doorbell,
 };
+#endif
 
+#if TARGET_PLATFORM == 3
 static void enable_ns_mcn_pmu(void)
 {
 	/*