Makefile: install bios-microvm like other binary blobs

Makefile: install bios-microvm like other binary blobs

Commit 0d5fae3e52e introduced bios-microvm.bin but forgot to add
it to the list of blobs being installed.
Add it to the list of BLOBS that get installed.

Fixes: 0d5fae3e52e "roms: add microvm-bios (qboot) as binary"
Signed-off-by: Bruce Rogers <brogers@suse.com>
[PMD: Reworded description]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Message-Id: <20191102114346.6445-1-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>