[media] radio-usb-si4713: fix sparse non static symbol warnings

Fixes the following sparse warnings:

drivers/media/radio/si4713/radio-usb-si4713.c:226:31: warning:
symbol 'start_seq' was not declared. Should it be static?
drivers/media/radio/si4713/radio-usb-si4713.c:291:29: warning:
symbol 'command_table' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/radio/si4713/radio-usb-si4713.c

···
  * (0x03): Get serial number of the board (Response : CB000-00-00)
  * (0x06, 0x03, 0x03, 0x08, 0x01, 0x0f) : Get Component revision
  */
-struct si4713_start_seq_table start_seq[] = {
+static struct si4713_start_seq_table start_seq[] = {
 
 	{ 1, { 0x03 } },
 	{ 2, { 0x32, 0x7f } },
···
  *	Byte 4 : Number of arguments + 1 (for the command byte)
  *	Byte 5 : Number of response bytes
  */
-struct si4713_command_table command_table[] = {
+static struct si4713_command_table command_table[] = {
 
 	{ SI4713_CMD_POWER_UP,		{ 0x00, SI4713_PWUP_NARGS + 1, SI4713_PWUP_NRESP} },
 	{ SI4713_CMD_GET_REV,		{ 0x03, 0x01, SI4713_GETREV_NRESP } },