spice-deps: Make LZ4 check depending on function
spice-deps: Make LZ4 check depending on function

LZ4 changed versioning scheme from r131 to v1.7.3 making our configure
fail with (1.7.3 < 129).

Switch from version checking to checking that the necessary function
is available.

Acked-by: Frediano Ziglio <55d48b080b2e443e395cde84d2c83b135a4ff48e@redhat.com>

fgouget/spice-common,fgouget/spice-common,fgouget/spice-common,fgouget/spice-common