manibuilder/alpine: Optionally add meson

Meson is available since Alpine v3.7.

Change-Id: I19f0c040d6a64abaf2c284d4159ec2d87fa6ee71
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/73404
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
1 file changed