qcacmn: Check whether Spectral is disabled upon setting rxchainmask

When Spectral is disabled via INI and the rxchainmask is set for
the radio via iwpriv/cfg80211tool, it results in null pointer access
of target_if_spectral pointer. To fix this, add Spectral feature check
inside target_if_spectral_set_rxchainmask.

Change-Id: Ibd43d3bbc8622d4b8502653b55511bb4667cec7a
CRs-Fixed: 2380653
3 files changed