bcm63xx_enet: Use platform_get_irq() to get the interrupt

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on
static allocation of IRQ resources in DT core code, this
causes an issue when using hierarchical interrupt domains
using "interrupts" property in the node as this bypassed
the hierarchical setup and messed up the irq chaining.

In preparation for removal of static setup of IRQ resource
from DT core code use platform_get_irq().

Signed-off-by: Meng Tang <tangmeng@uniontech.com>
Link: https://lore.kernel.org/r/20220303100815.25605-1-tangmeng@uniontech.com


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