video: driver: add resource ops macro support

Added call_res_op() macro and used at all possible
places to avoid invalid pointer dereference issue.

Also added changes to cleanup unused functions.

Change-Id: Id77711ad9eaf7b407208567b0fde1f2693588641
Signed-off-by: Govindaraj Rajagopal <quic_grajagop@quicinc.com>

driver/vidc/inc/resources.h

@@ -197,6 +197,10 @@ struct msm_vidc_resource {
 	int                        fw_cookie;
 };
 
+#define call_res_op(c, op, ...)                  \
+	(((c) && (c)->res_ops && (c)->res_ops->op) ? \
+	((c)->res_ops->op(__VA_ARGS__)) : 0)
+
 struct msm_vidc_resources_ops {
 	int (*init)(struct msm_vidc_core *core);