The tegra114 driver has a weird/separate `tegra_spi_transfer_delay()`
function that does 2 delays: one mdelay() and one udelay().

This was introduced via commit f4fade12
("spi/tegra114: Correct support for cs_change").

There doesn't seem to be a mention in that commit message to suggest a
specific need/use-case for having the 2 delay calls.
For the most part, udelay() should be sufficient.

This change replaces it with the new `spi_transfer_delay_exec()`, which
should do the same thing.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-11-alexandru.ardelean@analog.comSigned-off-by: Mark Brown <broonie@kernel.org>