dmaengine: hsu: Use GENMASK() consistently

For the masks replace chain of BIT() macros by GENMASK().
While at it, explicitly include bits.h.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220713172235.22611-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>