Makefile: don't use $(CC) before value is explicit set

Unless specified in the environment, $(CC) expands to some generic
host C compiler like cc or c99. We set our own value for $(CC), but
only few lines later.

Move the first use of the $(CC) variable behind the definition to
correct this.

Change-Id: I45344e063d21ddfe22b7ad77954e85c1c46087bd
Fixes: 1684b873

 ("Use clang assembler when clang compiler is used")
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

Makefile

@@ -84,26 +84,6 @@ endif
 
 export Q ECHO
 
-# Process Debug flag
-$(eval $(call add_define,DEBUG))
-ifneq (${DEBUG}, 0)
-        BUILD_TYPE	:=	debug
-        TF_CFLAGS	+= 	-g
-
-        ifneq ($(findstring clang,$(notdir $(CC))),)
-             ASFLAGS		+= 	-g
-        else
-             ASFLAGS		+= 	-g -Wa,--gdwarf-2
-        endif
-
-        # Use LOG_LEVEL_INFO by default for debug builds
-        LOG_LEVEL	:=	40
-else
-        BUILD_TYPE	:=	release
-        # Use LOG_LEVEL_NOTICE by default for release builds
-        LOG_LEVEL	:=	20
-endif
-
 # Default build string (git branch and commit)
 ifeq (${BUILD_STRING},)
         BUILD_STRING	:=	$(shell git describe --always --dirty --tags 2> /dev/null)
@@ -243,6 +223,26 @@ TF_CFLAGS_aarch64	=	$(march64-directive)
 LD			=	$(LINKER)
 endif
 
+# Process Debug flag
+$(eval $(call add_define,DEBUG))
+ifneq (${DEBUG}, 0)
+        BUILD_TYPE	:=	debug
+        TF_CFLAGS	+= 	-g
+
+        ifneq ($(findstring clang,$(notdir $(CC))),)
+             ASFLAGS		+= 	-g
+        else
+             ASFLAGS		+= 	-g -Wa,--gdwarf-2
+        endif
+
+        # Use LOG_LEVEL_INFO by default for debug builds
+        LOG_LEVEL	:=	40
+else
+        BUILD_TYPE	:=	release
+        # Use LOG_LEVEL_NOTICE by default for release builds
+        LOG_LEVEL	:=	20
+endif
+
 ifeq (${AARCH32_INSTRUCTION_SET},A32)
 TF_CFLAGS_aarch32	+=	-marm
 else ifeq (${AARCH32_INSTRUCTION_SET},T32)