spi: stm32-qspi: Replace of_gpio_named_count() by gpiod_count()

As a preparation to unexport of_gpio_named_count(), convert the
driver to use gpiod_count() instead.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20220830182821.47919-1-andriy.shevchenko@linux.intel.com


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