qcacmn: spectral: Fix misspelling of 'frequency'

Address the following issue in wlan_spectral_utils_api.h:
CHECK: 'frequncy' may be misspelled - perhaps 'frequency'?

Change-Id: Ie9675796d12feded20d968d09c439f2e6ac5c9f0
CRs-Fixed: 2241582
diff --git a/spectral/dispatcher/inc/wlan_spectral_utils_api.h b/spectral/dispatcher/inc/wlan_spectral_utils_api.h
index a619af2..9ecee05 100644
--- a/spectral/dispatcher/inc/wlan_spectral_utils_api.h
+++ b/spectral/dispatcher/inc/wlan_spectral_utils_api.h
@@ -98,7 +98,7 @@
 int16_t spectral_vdev_get_chan_freq(struct wlan_objmgr_vdev *vdev);
 
 /**
- * spectral_vdev_get_sec20chan_freq_mhz - Get vdev secondary channel frequncy
+ * spectral_vdev_get_sec20chan_freq_mhz - Get vdev secondary channel frequency
  * @vdev:   vdev object
  * @sec20chan_freq: secondary channel frequency
  *