libraw: add patch to remove Byte order mark

This Byte order mark is not recognized by gcc < 4.4, which is the case
on Blackfin where gcc 4.3.x is used. Since this BOM is not useful
anyway, we simply remove it. The patch has been submitted upstream.

Fixes:

  http://autobuild.buildroot.net/results/143c4c2a1d8527c97362ce11507e8b5a79dd0d6b/



Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>