mmc: mmci: Add support for SW busy-end timeouts

The ux500 variant doesn't have a HW based timeout to use for busy-end IRQs.
To avoid hanging and waiting for the card to stop signaling busy, let's
schedule a delayed work, according to the corresponding cmd->busy_timeout
for the command. If the work gets to run, let's kick the IRQ handler to
complete the currently running request/command.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20230620091113.33393-1-ulf.hansson@linaro.org