irqchip/irq-pruss-intc: Add support for ICSSG INTC on K3 SoCs

irqchip/irq-pruss-intc: Add support for ICSSG INTC on K3 SoCs

The K3 AM65x and J721E SoCs have the next generation of the PRU-ICSS IP,
commonly called ICSSG. The PRUSS INTC present within the ICSSG supports
more System Events (160 vs 64), more Interrupt Channels and Host Interrupts
(20 vs 10) compared to the previous generation PRUSS INTC instances. The
first 2 and the last 10 of these host interrupt lines are used by the
PRU and other auxiliary cores and sub-modules within the ICSSG, with 8
host interrupts connected to MPU. The host interrupts 5, 6, 7 are also
connected to the other ICSSG instances within the SoC and can be
partitioned as per system integration through the board dts files.

Enhance the PRUSS INTC driver to add support for this ICSSG INTC
instance.

Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>