mmc: meson-gx: fix deferred probing

The driver overrides the error codes and IRQ0 returned by platform_get_irq()
to -EINVAL, so if it returns -EPROBE_DEFER, the driver will fail the probe
permanently instead of the deferred probing. Switch to propagating the error
codes upstream.  Since commit ce753ad1 ("platform: finally disallow IRQ0
in platform_get_irq() and its ilk") IRQ0 is no longer returned by those APIs,
so we now can safely ignore it...

Fixes: cbcaac6d

 ("mmc: meson-gx-mmc: Fix platform_get_irq's error checking")
Cc: stable@vger.kernel.org # v5.19+
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20230617203622.6812-3-s.shtylyov@omp.ru
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>