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>
diff --git a/util/manibuilder/Dockerfile.alpine b/util/manibuilder/Dockerfile.alpine
index 7b48277..a9bc5e3 100644
--- a/util/manibuilder/Dockerfile.alpine
+++ b/util/manibuilder/Dockerfile.alpine
@@ -12,7 +12,7 @@
 		ln -sf /etc/ssl/cert.pem /etc/ssl/certs/ca-certificates.crt; \
 	fi
 
-RUN apk add libgpiod-dev || true
+RUN apk add libgpiod-dev meson || true
 
 # fix weird permissions in armhf-v3.11
 RUN [ -d /usr/share/git-core/templates ] && \