qcacmn: Define new_ch_width in csa_offload_params as phy_ch_width
Currently sme_switch_channel set new_ch_width as phy_ch_width, while
wma_csa_offload_handler set new_ch_width as raw bit in wide bandwidth
channel switch IE.
Clean up the code. Define new_ch_width in csa_offload_params as
phy_ch_width.
Change-Id: Ie1999860421aa60c18cdc8059275954d910b4b66
CRs-Fixed: 3324746