Use FIELD_GET and FIELD_PREP to get access to the register fields. Delete
the shift macros and use GENMASK() for the touched macros.

Note that, this has the side-effect of changing the constants to 64-bit on
64-bit platforms.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Link: https://lore.kernel.org/r/20200511062828.1791484-1-yamada.masahiro@socionext.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>