buildroot: Update to 1455c21047b8c17372fa19d237ba5a28df9976d5

Jeremy Kerr (1):
      package/linux-firmware: Update to 38e5405c96d10bb42b629b45210c46166461fc21

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Merge pull request #35 from jk-ozlabs/master

buildroot: Update to 1455c21047b8c17372fa19d237ba5a28df9976d5