Add check for TianoCore EDK2 firmware for ARMv7
Add check for TianoCore EDK2 firmware for ARMv7

There's now TianoCore EDK2 firmwares for ARMv7 so add a check to
see if they're available in preparation of building UEFI enabled
ARMv7 images.

Signed-off-by: Peter Robinson <0cd2d1e82f6226d6d80917107cdcc165e1fecc43@gmail.com>

clalancette/oz,nullr0ute/oz,nullr0ute/oz,clalancette/oz