The original implementation of RPM handling in probe() was mostly
correct, except it failed to call pm_runtime_get_*() to activate the
hardware. The subsequent fix, 734882a8 ("spi: cadence: Correct
initialisation of runtime PM"), breaks the implementation further,
to the point where the system using this hard IP on ZynqMP hangs on
boot, because it accesses hardware which is gated off.

Undo 734882a8 ("spi: cadence: Correct initialisation of runtime
PM") and instead add missing pm_runtime_get_noresume() and move the
RPM disabling all the way to the end of probe(). That makes ZynqMP
not hang on boot yet again.

Fixes: 734882a8 ("spi: cadence: Correct initialisation of runtime PM")
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Charles Keepax <ckeepax@opensource.cirrus.com>
Cc: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210716182133.218640-1-marex@denx.deSigned-off-by: Mark Brown <broonie@kernel.org>