qcacmn: Add pdev param to set firmware to use lower chains for tx

Add new pdev param with which firmware can be set to use
a lower number of chains without doing a reset. In response
to this firmware's ratecontrol will select only rates
which can be sent using a lower number of chains, and set
the h/w tx descpriptor's chain select to whatever value
has been configured using this command.

CRs-Fixed: 2123206
Change-Id: Ice713393958c2c2acedba0fe2e9354f3fe3bee75
1 file changed