This prevents signed bitshift issues when the shift would overwrite the
signed bit, and prevents making this mistake in the future when copying
and modifying code.

Use GENMASK or the unsigned postfix for cases which aren't suitable for
BIT() macro.
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>