amd-xgbe: Use platform_irq_count()

The AMD XGbE driver currently counts the number of interrupts assigned
to the device by inspecting the pdev->resource array. Since commit
a1a2b712 ("of/platform: Drop static setup of IRQ resource from DT
core") removed IRQs from this array, the driver now attempts to get all
interrupts from 1 to -1U and gives up probing once it reaches an invalid
interrupt index.

Obtain the number of IRQs with platform_irq_count() instead.

Fixes: a1a2b712 ("of/platform: Drop static setup of IRQ resource from DT core")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20220609161457.69614-1-jean-philippe@linaro.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>