usb: renesas_usbhs: 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 bypasses the hierarchical setup and messes up the
irq chaining.

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

Drop irqflags member from struct usbhs_priv as this driver is used by
two non DT users sh7757lcr and ecovec24 which do not pass
IORESOURCE_IRQ_SHAREABLE as part of their pdata. Along this drop the
IRQF_SHARED flag handling in the code.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211220010411.12075-3-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>