For some devices, the result of the flow control high watermark gets
truncated when programming it into the registers because of the mask used.
Switch the mask to 32-bit to prevent this from happening.
Signed-off-by: Matthew Vick <matthew.vick@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>