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 <pbrobinson@gmail.com>

oz/ozutil.py

@@ -1061,6 +1061,9 @@ def exists(self):
                           '/usr/share/edk2/aarch64/vars-template-pflash.raw'),
                      UEFI('/usr/share/edk2.git/aarch64/QEMU_EFI-pflash.raw',
                           '/usr/share/edk2.git/aarch64/vars-template-pflash.raw')]
+    elif arch in ['armv7l']:
+        uefi_list = [UEFI('/usr/share/edk2/arm/QEMU_EFI-pflash.raw',
+                          '/usr/share/edk2/arm/vars-template-pflash.raw')]
     else:
         raise Exception("Invalid arch for UEFI firmware")