remoteproc/pru: Introduce new vendor interrupt resource for K3 SoCs

The PRU-ICSS IP present within K3 AM65x and J721E SoCs, commonly called
ICSSG, has an INTC that supports more System Events (160 vs 64), more
Interrupt Channels and Host Interrupts (20 vs 10) compared to the current
generation PRUSS INTC instances. The current custom vendor interrupt
resource configuration used by the pru_rproc driver is not adequate to
support this ICSSG INTC.

Add a new version of the custom vendor interrupt resource named
fw_rsc_custom_intrmap_k3 and enhance the pru_handle_vendor_intrmap()
function to add support for configuring this newer INTC sub-module.
This new resource structure is a revised version of the existing
fw_rsc_custom_intrmap resource, with additional fields for the
increased number of channels. Support for both resource types is
provided through the PRUSS_RSC_INTRS vendor resource type and
distinguished using a version field in the sub_type.

Signed-off-by: Suman Anna <s-anna@ti.com>