There are a lot of pre-existing typechecking warnings around the
access and assign of elements of ptd structure of __dw type.

sparse: warning: invalid assignment: |=
sparse:    left side has type restricted __dw
sparse:    right side has type unsigned int

or

warning: restricted __dw degrades to integer

or

sparse: warning: incorrect type in assignment (different base types)
sparse:    expected restricted __dw [usertype] dw4
sparse:    got unsigned int [assigned] [usertype] usof

To handle this, annotate conversions along the {TO,FROM}_DW* macros
and some assignments and function arguments.

This clean up completely all sparse warnings for this driver.
Signed-off-by: NRui Miguel Silva <rui.silva@linaro.org>
Link: https://lore.kernel.org/r/20210513084717.2487366-2-rui.silva@linaro.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>