GitLab

Allow to handle GZIP-compressed images by giving FIP_GZIP=1 from the
command line.

- Images are GZIP-compressed, then packed into FIP.  If Trusted Board
  Boot is enabled, certificates are generated based on the compressed
  images.

- GZIP decompressor is linked into BL2 to decompress images at
  run-time.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>