feat(plat/arm): Introduce TC1 platform

This renames tc0 platform folder and files to tc, and introduces
TARGET_PLATFORM variable to account for the differences between
TC0 and TC1.

Signed-off-by: Usama Arif <usama.arif@arm.com>
Change-Id: I5b4a83f3453afd12542267091b3edab4c139c5cd
diff --git a/fdts/tc0.dts b/fdts/tc.dts
similarity index 99%
rename from fdts/tc0.dts
rename to fdts/tc.dts
index 9051b7b..f66d556 100644
--- a/fdts/tc0.dts
+++ b/fdts/tc.dts
@@ -7,7 +7,7 @@
 /dts-v1/;
 
 / {
-	compatible = "arm,tc0";
+	compatible = "arm,tc";
 	interrupt-parent = <&gic>;
 	#address-cells = <2>;
 	#size-cells = <2>;