board: nanopi-r76s: add initial Armbian support (#8586)

Add board configuration for FriendlyELEC NanoPi R76S, including:
- nanopi-r76s.conf with board parameters and boot settings
- initial kernel / U-Boot patch for device tree and board bring-up

config/boards/nanopi-r76s.conf

@@ -0,0 +1,21 @@
+# Rockchip RK3576 SoC octa core 2-4-16GB RAM SoC 2x 2.5GbE eMMC USB3 WIFI
+BOARD_NAME="NanoPi R76S"
+BOARDFAMILY="rk35xx"
+BOOTCONFIG="nanopi-r76s-rk3576_defconfig"
+KERNEL_TARGET="vendor" # WIP: current & edge kernel
+FULL_DESKTOP="yes"
+BOOT_LOGO="desktop"
+BOOT_FDT_FILE="rockchip/rk3576-nanopi-r76s.dtb"
+BOOT_SCENARIO="spl-blobs"
+SERIALCON="ttyS0"
+IMAGE_PARTITION_TABLE="gpt"
+BOARD_MAINTAINER="SuperKali"
+
+
+function post_family_tweaks__nanopi-r76s_naming_audios() {
+	display_alert "$BOARD" "Renaming NanoPi R76S audio" "info"
+
+	mkdir -p $SDCARD/etc/udev/rules.d/
+	echo 'SUBSYSTEM=="sound", ENV{ID_PATH}=="platform-hdmi-sound", ENV{SOUND_DESCRIPTION}="HDMI Audio"' > $SDCARD/etc/udev/rules.d/90-naming-audios.rules
+	return 0
+}