mmc: mtk-sd: use GENMASK and FIELD macros

mmc: mtk-sd: use GENMASK and FIELD macros

Replace separate mask and shift definitions with GENMASK and FIELD_*
macros for better readability and maintainability.

All macros ending in _M have the suffix dropped. The value remains the
same but is now generated with GENMASK. All macros ending in _S are
removed and their uses replaced with FIELD_PREP and FIELD_GET macros.

Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Macpaul Lin <macpaul.lin@mediatek.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>