spi: stm32: enable pm_runtime autosuspend

This commit enables the pm_runtime autosuspend
and sets a 1ms autosuspend delay.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Link: https://lore.kernel.org/r/1625646426-5826-3-git-send-email-alain.volmat@foss.st.com


Signed-off-by: Mark Brown <broonie@kernel.org>