install-ffmpeg-ios.sh: Add named parameters


This patch gives optional named parameters to install-ffmpeg-ios.sh,
making it easier to run locally.

Minimal changes to CI behavior.

Pick-to: 6.12
Change-Id: I76a611317a336f0586c5b421629e01760da38ee6
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
commit6974ce7eb00e0793028941bf5d94e854d11e6dd1
parent827183ba5782c34fd9584bf7bed83ba5366de991
authorNils Petter Skålerud <nils.petter.skalerud@qt.io>
committerNils Petter Skålerud <nils.petter.skalerud@qt.io>
commit timeFri, 9 Oct 2026 08:59:23 +0000