Add support to configure spectral scan bandwidth as provided by the user.
Validate the user configured value before applying it. As the spectral scan
bandwidth is an optional parameter, when the user doesn't configure it, use
configure the spectral scan bandwidth to the maximum value supported by the
target for the current operating bandwidth.
Also, populate the spectral scan bandwidths supported for different
operating bandwidths on different targets.
CRs-Fixed: 3042424
Change-Id: I266aa5489b0ce5c149968067a06e1cc65bb4e3b7
aead8c4d39