uwb: Staticize local symbols

These local symbols are used only in this file.
Fix the following sparse warnings:

drivers/uwb/drp-ie.c:30:5: warning: symbol 'uwb_rsv_reason_code' was not declared. Should it be static?
drivers/uwb/drp-ie.c:58:5: warning: symbol 'uwb_rsv_companion_reason_code' was not declared. Should it be static?

Signed-off-by: Jingoo Han <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/uwb/drp-ie.c

···
 /*
  * Return the reason code for a reservations's DRP IE.
  */
-int uwb_rsv_reason_code(struct uwb_rsv *rsv)
+static int uwb_rsv_reason_code(struct uwb_rsv *rsv)
 {
 	static const int reason_codes[] = {
 		[UWB_RSV_STATE_O_INITIATED]          = UWB_DRP_REASON_ACCEPTED,
···
 /*
  * Return the reason code for a reservations's companion DRP IE .
  */
-int uwb_rsv_companion_reason_code(struct uwb_rsv *rsv)
+static int uwb_rsv_companion_reason_code(struct uwb_rsv *rsv)
 {
 	static const int companion_reason_codes[] = {
 		[UWB_RSV_STATE_O_MOVE_EXPANDING]     = UWB_DRP_REASON_ACCEPTED,