can: peak_canfd: Remove unused macros

CANFD_CLK_SEL_DIV_MASK and CANFD_OPTIONS_SET are
never used after they were introduced. Remove them.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Link: https://lore.kernel.org/r/20200904131247.23021-1-wanghai38@huawei.com


[mkl: keep CANFD_CLK_SEL_DIV_MASK for documentation purpose]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>