fix map entry and .h declaration for gsm0808_chan_type_to_speech_codec()

Recent commit 3149b0d076477303a38df735fe579b1b06ee17b2 adds function
gsm0808_chan_type_to_speech_codec() but adds a completely mismatching name in
libosmogsm.map, as well as a definition with a typo in the name.

Fix the entry in libosmogsm.map.

Add the missing 'c' in gsm0808_utils.h

Change-Id: I5a621fa5ef6b632eabbe224f3dd383eacaffb695
diff --git a/include/osmocom/gsm/gsm0808_utils.h b/include/osmocom/gsm/gsm0808_utils.h
index 57ba171..17a03f5 100644
--- a/include/osmocom/gsm/gsm0808_utils.h
+++ b/include/osmocom/gsm/gsm0808_utils.h
@@ -50,6 +50,6 @@
 				 const struct gsm0808_cell_id_list *cil);
 int gsm0808_dec_cell_id_list(struct gsm0808_cell_id_list *cil,
 			     const uint8_t *elem, uint8_t len);
-int gsm0808_chan_type_to_speech_code(uint8_t perm_spch);
+int gsm0808_chan_type_to_speech_codec(uint8_t perm_spch);
 int gsm0808_speech_codec_from_chan_type(struct gsm0808_speech_codec *sc,
 					uint8_t perm_spch);