airoha: Introduce EN7581 SoC support

Introduce EN7581 SoC support with currently rfb board supported.

This is a new 64bit SoC from Airoha that is currently almost fully
supported upstream with only the DTS missing. Setting source-only
waiting for the full upstream support to be completed.

Link: https://github.com/openwrt/openwrt/pull/16730
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

target/linux/airoha/modules.mk

@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+OTHER_MENU:=Other modules
+
+I2C_MT7621_MODULES:= \
+  CONFIG_I2C_MT7621:drivers/i2c/busses/i2c-mt7621
+
+define KernelPackage/i2c-en7581
+  SUBMENU:=$(OTHER_MENU)
+  $(call i2c_defaults,$(I2C_MT7621_MODULES),79)
+  TITLE:=Airoha I2C Controller
+  DEPENDS:=+kmod-i2c-core \
+	  @(TARGET_airoha_en7581)
+endef
+
+define KernelPackage/i2c-en7581/description
+ Kernel modules for enable mt7621 i2c controller.
+endef
+
+$(eval $(call KernelPackage,i2c-en7581))
+
+
+define KernelPackage/pwm-en7581
+  SUBMENU:=$(OTHER_MENU)
+  TITLE:=Airoha EN7581 PWM
+  DEPENDS:=@(TARGET_airoha_en7581)
+  KCONFIG:= \
+        CONFIG_PWM=y \
+        CONFIG_PWM_AIROHA=y \
+        CONFIG_PWM_SYSFS=y
+  FILES:= \
+        $(LINUX_DIR)/drivers/pwm/pwm-airoha.ko
+  AUTOLOAD:=$(call AutoProbe,pwm-airoha)
+endef
+
+define KernelPackage/pwm-en7581/description
+ Kernel module to use the PWM channel on Airoha SoC
+endef
+
+$(eval $(call KernelPackage,pwm-en7581))
+
+