Enable required am62x binaries to be cross-compiled on any architecture.

Building of the am62x binaries was being restricted to the armhf arch as these are 32-bit arm binaries, however this is boot firmware for a predominently arm64 device and we wish to have these available when not necessarily compiling the armhf arch. Switch to being able to cross compile on any arch.

Signed-off-by: Martyn Welch martyn.welch@collabora.com