drivers: interrupt_controller: Add driver for NXP's IRQ_STEER IP

This commit introduces a new interrupt controller driver used
for NXP's IRQ_STEER IP.

Apart from introducing the driver itself, this commit contains
the following changes:
	1) Switch i.MX8MP to using the XTENSA core interrupt
	controller instead of the dummy irqsteer one.
		* this is required because the binding for the
		irqsteer driver is no longer a dummy one
		(since it's being used by the irqsteer driver).
		As such, to avoid having problems, switch to
		using another dummy binding.
	2) Modify the irqsteer dummy binding such that it
	serves the IRQ_STEER driver's needs.

Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

drivers/interrupt_controller/CMakeLists.txt

@@ -37,6 +37,7 @@ zephyr_library_sources_ifdef(CONFIG_NXP_S32_WKPU            intc_wkpu_nxp_s32.c)
 zephyr_library_sources_ifdef(CONFIG_XMC4XXX_INTC            intc_xmc4xxx.c)
 zephyr_library_sources_ifdef(CONFIG_NXP_PINT                intc_nxp_pint.c)
 zephyr_library_sources_ifdef(CONFIG_RENESAS_RA_ICU          intc_ra_icu.c)
+zephyr_library_sources_ifdef(CONFIG_NXP_IRQSTEER            intc_nxp_irqsteer.c)
 
 if(CONFIG_INTEL_VTD_ICTL)
   zephyr_library_include_directories(${ZEPHYR_BASE}/arch/x86/include)

drivers/interrupt_controller/Kconfig

@@ -104,4 +104,6 @@ source "drivers/interrupt_controller/Kconfig.vim"
 
 source "drivers/interrupt_controller/Kconfig.ra"
 
+source "drivers/interrupt_controller/Kconfig.nxp_irqsteer"
+
 endmenu

drivers/interrupt_controller/Kconfig.nxp_irqsteer

@@ -0,0 +1,26 @@
+# Copyright 2023 NXP
+# SPDX-License-Identifier: Apache-2.0
+
+config NXP_IRQSTEER
+	bool "IRQ_STEER interrupt controller for NXP chips"
+	default y
+	depends on DT_HAS_NXP_IRQSTEER_INTC_ENABLED
+	depends on MULTI_LEVEL_INTERRUPTS
+	depends on XTENSA
+	help
+		The IRQSTEER INTC provides support for MUX-ing
+		multiple interrupts from peripheral to one or
+		more CPU interrupt lines. This is used for CPUs
+		such as XTENSA DSPs.
+
+config NXP_IRQSTEER_ISR_THRESHOLD
+	int "Error threshold for a dispatcher's ISR"
+	default 5
+	depends on NXP_IRQSTEER
+	help
+		This config controls how many times a
+		dispatcher's ISR is allowed to iterate
+		over its assigned interrupt status register
+		before it can conclude that an interrupt
+		will get retriggered ad-infinitum (or at
+		least for an unacceptable number of times).