mmp_pdma: Style neatening

Neaten code used as a template for other drivers.
Make the code more consistent with kernel styles.

o Convert #defines with (1<<foo) to BIT(foo)
o Alignment wrapping
o Logic inversions to put return at end of functions
o Convert devm_kzalloc with multiply to devm_kcalloc
o typo of Peripheral fix

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>