mobile: cosmetic: fix -Wswitch in tch_voice_state_init()

Not really critical, just make gcc happy:

tch_voice.c: In function ‘tch_voice_state_init’:
tch_voice.c:117:9: warning: enumeration value ‘TCH_VOICE_IOH_GAPK’ not handled in switch [-Wswitch]
  117 |         switch (state->handler) {
      |         ^~~~~~

Change-Id: I46afce396f730de26f21e0e4ec71e144aafd6beb
---
M src/host/layer23/src/mobile/tch_voice.c
1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/host/layer23/src/mobile/tch_voice.c b/src/host/layer23/src/mobile/tch_voice.c
index ac793e8..a740f71 100644
--- a/src/host/layer23/src/mobile/tch_voice.c
+++ b/src/host/layer23/src/mobile/tch_voice.c
@@ -122,8 +122,8 @@
 	case TCH_VOICE_IOH_LOOPBACK:
 		rr->audio_mode = AUDIO_RX_TRAFFIC_IND | AUDIO_TX_TRAFFIC_REQ;
 		break;
-#ifdef WITH_GAPK_IO
 	case TCH_VOICE_IOH_GAPK:
+#ifdef WITH_GAPK_IO
 		if ((cd->chan_nr & RSL_CHAN_NR_MASK) == RSL_CHAN_Bm_ACCHs)
 			state->gapk_io = gapk_io_state_alloc_mode_rate(ms, cd->mode, true);
 		else /* RSL_CHAN_Lm_ACCHs */

