FS#3654 - package/boot/arm-trusted-firmware-mvebu requires fetching binary cross compiler

[openwrt-bot]

hrw:

Supply the following if possible:

• Device problem occurs on

Any AArch64 host machine.

• Software versions of OpenWrt/LEDE release, packages, etc.

git HEAD (commit acbea54)

• Steps to reproduce

1. run 'make menuconfig'
2. select 'Marvell EBU Armada' -> 3700P -> 'Marvell Espressobin non-eMMC'
3. run 'make'

At some moment it will fail on attempt to fetch Linaro's build of cross compiler. Which is available only for x86-64 host architecture.

OpenWRT should build own cross compiler instead of relying on external one.