video: driver: implement module remove function

Implement remove function to unregister video device,
unregister v4l2 device, remove sysfs group, deinit
irq, platform, dt, core.

Change-Id: Ib713b0b66500aafcfb5f0500b9ce7285b9640311
Signed-off-by: Darshana Patil <darshana@codeaurora.org>

driver/variant/iris2/inc/msm_vidc_iris2.h

@@ -13,3 +13,4 @@ int msm_vidc_init_iris2(struct msm_vidc_core *core);
 //	return -EINVAL;
 //}
 //#endif
+int msm_vidc_deinit_iris2(struct msm_vidc_core *core);

driver/variant/iris2/src/msm_vidc_iris2.c

@@ -519,3 +519,9 @@ int msm_vidc_init_iris2(struct msm_vidc_core *core)
 
 	return 0;
 }
+
+int msm_vidc_deinit_iris2(struct msm_vidc_core *core)
+{
+	/* do nothing */
+	return 0;
+}