build: qcom_target: Define MASTER_SIDE_CP_TARGET_LIST

Currently, in the display HAL, we're replacing the usage
of this variable with a check for TARGET_BOARD_PLATFORM.

Instead of having to do that every time a new branch is made,
define the variable in qcom_target.

Change-Id: Iddcc38c70adc52267e70c985b7a0ad3d8c4c8929

build/core/qcom_target.mk

@@ -61,6 +61,9 @@ ifeq ($(BOARD_USES_QCOM_HARDWARE),true)
         TARGET_USES_COLOR_METADATA := true
     endif
 
+    # List of targets that use master side content protection
+    MASTER_SIDE_CP_TARGET_LIST := msm8996 msm8998
+
     TARGET_GLOBAL_CFLAGS += $(qcom_flags)
     TARGET_GLOBAL_CPPFLAGS += $(qcom_flags)
     CLANG_TARGET_GLOBAL_CFLAGS += $(qcom_flags)