qcacld-3.0: Convert HDD/SME/CSR legacy channel ID usage

1) Change the following functions' signatures and/or code
   to make them using frequencies instead of channel IDs:

   hdd_get_adapter_home_channel
   hdd_get_operating_channel
   wlan_hdd_request_pre_cac
   wlan_hdd_validate_and_get_pre_cac_ch
   __wlan_hdd_request_pre_cac
   hdd_check_and_disconnect_sta_on_invalid_channel
   set_first_connection_operating_channel
   sme_is_channel_valid
   csr_roam_is_channel_valid

2) Remove the declaration, definition and usage of
   csr_roam_is_chan_freq_valid, and replace it with
   csr_roam_is_channel_valid as this API does exactly
   the same thing.

3) Retain the code/logic for chan ID utilization in
   function set_first_connection_operating_channel as
   it is used to convert the parameters issued by
   user space apps.

4) Fix a few camel cases in csr_api_roam.c

Change-Id: I4f9cfa21a5f40288ad9492ac8be7939ed8eb6484
CRs-Fixed: 2565002
11 files changed