debian/rules: drop unused COMPILE* variables

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

debian/rules

 #!/usr/bin/make -f
 
-export COMPILE = aarch64-linux-gnu-
-
 export PLATFORM = k3-am62x
 
 export CFG_ARM64_core = y
@@ -17,6 +15,5 @@ export CFG_USER_TA_TARGETS = ta_arm64
 
 override_dh_auto_build:
 	make \
-	    CROSS_COMPILE=${COMPILE32} \
             PLATFORM=${PLATFORM} \
             CFG_ARM64_core=${CFG_ARM64_core}