drm/i915/gvt: mark symbols static where possible

Mark all local functions & variables as static.

Signed-off-by: Du, Changbin <changbin.du@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/gvt/cmd_parser.c b/drivers/gpu/drm/i915/gvt/cmd_parser.c
index 0d322e0..aafb57e 100644
--- a/drivers/gpu/drm/i915/gvt/cmd_parser.c
+++ b/drivers/gpu/drm/i915/gvt/cmd_parser.c
@@ -480,8 +480,8 @@
 #define gmadr_dw_number(s)	\
 	(s->vgpu->gvt->device_info.gmadr_bytes_in_cmd >> 2)
 
-unsigned long bypass_scan_mask = 0;
-bool bypass_batch_buffer_scan = true;
+static unsigned long bypass_scan_mask = 0;
+static bool bypass_batch_buffer_scan = true;
 
 /* ring ALL, type = 0 */
 static struct sub_op_bits sub_op_mi[] = {
@@ -960,7 +960,7 @@
 	int mi_user_interrupt;
 };
 
-struct cmd_interrupt_event cmd_interrupt_events[] = {
+static struct cmd_interrupt_event cmd_interrupt_events[] = {
 	[RCS] = {
 		.pipe_control_notify = RCS_PIPE_CONTROL,
 		.mi_flush_dw = INTEL_GVT_EVENT_RESERVED,