tools/lz4: build with meson

tools/lz4: build with meson

Simplifies Makefile and speeds up compilation.

Before:
Executed in   68.00 secs    fish           external
   usr time  104.17 secs    1.33 millis  104.17 secs
   sys time    4.29 secs    0.35 millis    4.29 secs

After:
Executed in   27.98 secs    fish           external
   usr time   25.18 secs    1.32 millis   25.18 secs
   sys time    3.31 secs    0.35 millis    3.31 secs

Signed-off-by: Rosen Penev <rosenp@gmail.com>