scripts: use aports rpi bootloader

scripts/mkimg.arm.sh

 build_rpi_blobs() {
-	local fw
-	for fw in bootcode.bin fixup.dat start.elf ; do
-		curl --remote-time https://raw.githubusercontent.com/raspberrypi/firmware/${rpi_firmware_commit}/boot/${fw} \
-			--output "${DESTDIR}"/${fw} || return 1
-	done
+	apk fetch --quiet --stdout raspberrypi-bootloader | tar -C "${DESTDIR}" -zx --strip=1 boot/
 }
 
 rpi_gen_cmdline() {
@@ -47,6 +43,7 @@ rpi_gen_config() {
 		# uncomment line to enable serial on ttyS0 on rpi3
 		# NOTE: This fixes the core_freq to 250Mhz
 		# enable_uart=1
+		include usercfg.txt
 		EOF
 	;;
 	esac
@@ -58,9 +55,8 @@ build_rpi_config() {
 }
 
 section_rpi_config() {
-	[ -n "$rpi_firmware_commit" ] || return 0
 	build_section rpi_config $( (rpi_gen_cmdline ; rpi_gen_config) | checksum )
-	build_section rpi_blobs "$rpi_firmware_commit"
+	build_section rpi_blobs
 }
 
 profile_rpi() {
@@ -71,9 +67,6 @@ profile_rpi() {
 		And much more..."
 	image_ext="tar.gz"
 	arch="aarch64 armhf"
-	# check commit log for matching commit with current rpi kernel version at:
-	# https://github.com/raspberrypi/firmware/tree/master
-	rpi_firmware_commit="eeaaf5e2b5aee29f31e989c0dddd186fb68b2144"
 	kernel_flavors="rpi"
 	case "$ARCH" in
 		armhf) kernel_flavors="$kernel_flavors rpi2";;