copy-firmware: Introduce 'RawFile' keyword

copy-firmware: Introduce 'RawFile' keyword

Currently, 'Raw: <filename>' needs to be added to WHENCE for files that
must not be compressed. This means that such files need to be listed
twice ('File: <filename>' and 'Raw: <filename>') which is not pretty and
error prone. Also, the current implementation is broken for filenames
that contain quotes (") and it also requires grep'ing of WHENCE for every
processed line which slows things down.

Fix all of the above by introducing a new keyword 'RawFile' so that such
files are listed only once, quotes are handled correctly and grep is no
longer needed.

Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Signed-off-by: Josh Boyer <jwboyer@kernel.org>