Makefile: install bios-microvm like other binary blobs

Commit 0d5fae3e 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: 0d5fae3e "roms: add microvm-bios (qboot) as binary"
Signed-off-by: NBruce Rogers <brogers@suse.com>
[PMD: Reworded description]
Signed-off-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NStefano Garzarella <sgarzare@redhat.com>
Reviewed-by: NSergio Lopez <slp@redhat.com>
Message-Id: <20191102114346.6445-1-philmd@redhat.com>
Signed-off-by: NLaurent Vivier <laurent@vivier.eu>

Makefile

@@ -771,7 +771,7 @@ de-ch  es     fo  fr-ca  hu     ja  mk  pt  sl     tr \
 bepo    cz
 
 ifdef INSTALL_BLOBS
-BLOBS=bios.bin bios-256k.bin sgabios.bin vgabios.bin vgabios-cirrus.bin \
+BLOBS=bios.bin bios-256k.bin bios-microvm.bin sgabios.bin vgabios.bin vgabios-cirrus.bin \
 vgabios-stdvga.bin vgabios-vmware.bin vgabios-qxl.bin vgabios-virtio.bin \
 vgabios-ramfb.bin vgabios-bochs-display.bin vgabios-ati.bin \
 ppc_rom.bin openbios-sparc32 openbios-sparc64 openbios-ppc QEMU,tcx.bin QEMU,cgthree.bin \