Draft: amazon-otter: add new device

This merge requests adds support to 1st generation Kindle Fire with mainline Linux support (v5.11.0).

I will update the wiki with an installation guide at some point. For now, it is written in my documentation repo here.

Status:

• kernel 5.11.0 works
• pmOS boots
• wifi works; requires nonfree TI firmware
• display panel works
• omapdrm/framebuffer works
• panel backlight partially works: on/off support only
• touchscreen works
• USB OTG and CDC/ACM works
• Debug UART works
• battery fuel gauge works
• charger controller works
• temperature sensor works
• green and orange leds work
• RTC works
• acclerometer works
• no GPU acceleration
• no PWM backlight control
• no light sensor support
• no audio support
• no rproc support

I am still exploring booting options and deciding whether I want an Android boot image or u-boot scripts.

device/testing/device-amazon-otter/APKBUILD

+# Reference: <https://postmarketos.org/devicepkg>
+# Maintainer: Hansem Ro <hansemro@outlook.com>
+pkgname=device-amazon-otter
+pkgdesc="Amazon Kindle Fire"
+pkgver=0.1
+pkgrel=0
+url="https://postmarketos.org"
+license="MIT"
+arch="armv7"
+options="!check !archcheck"
+depends="
+	linux-amazon-otter
+	postmarketos-base
+	u-boot-tools
+"
+makedepends="devicepkg-dev"
+subpackages="
+	$pkgname-x11
+	$pkgname-nonfree-firmware:nonfree_firmware
+"
+
+source="
+	deviceinfo
+	xorg.conf
+	uboot-script.cmd
+"
+
+build() {
+	devicepkg_build $startdir $pkgname
+	mkimage -A arm -O linux -T script -C none -a 0 -e 0 -n postmarketos -d "$srcdir"/uboot-script.cmd "$srcdir"/boot.scr
+}
+
+package() {
+	devicepkg_package $startdir $pkgname
+	install -D -m644 "$srcdir"/boot.scr \
+		"$pkgdir"/boot/boot.scr
+}
+
+x11() {
+	install_if="$pkgname xorg-server"
+	install -D -m644 "$srcdir"/xorg.conf \
+		"$subpkgdir"/etc/X11/xorg.conf.d/11-otter.conf
+}
+
+nonfree_firmware() {
+	pkgdesc="WiFi firmware"
+	depends="linux-firmware-ti-connectivity"
+	mkdir "$subpkgdir"
+}
+
+sha512sums="
+cf932af1696a948d0f53301ab4589591e5875b1c665c594c7c36f3bdf18c42c55ef07c2c071d52583309692030e23cdde7a064f34dbc702527e4b8a13959bb26  deviceinfo
+f15d7ef2f8a3fefb8f2f5b3276f0c1cf2364a34f36d18600d57f294169d2159d5180d5fa530faa2853abd591f17693ee49cecbf0f21ee9ee372b4868b3b65639  xorg.conf
+11259025d70879de44981c3ebf79a96a05b4fe883d806839a98773bea7521cbf277c82e2212598dfc9146cc16f41cefa122e423947efbe3d0fba035e36143c51  uboot-script.cmd
+"