spi: meson-spicc: move wait completion in driver to take bursts delay in account

Some delay occurs between each bursts, thus the default delay is wrong
and a timeout will occur with big enough transfers.

The solution is to handle the timeout management in the driver and
add some delay for each bursts in the timeout calculation.

Reported-by: Da Xue <da@libre.computer>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20221026-spicc-burst-delay-v1-0-1be5ffb7051a@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>