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
1 file changed