linux-firmware: fix tarball hash
Fixes:
http://autobuild.buildroot.net/results/8f6116799dcf9991e5e5253b404506b1439e0a7b/
http://autobuild.buildroot.net/results/d10/d10102bd728e368389ebef8eda7a3eb75caa7d4f/
Commit e14102c6f2f6eb31844 (linux-firmware: bump version and fix hash)
updated the git revision but used an invalid hash, causing download
failures.
Use the correct hash instead.
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>