Doom plugin: In anticipation of moving to the EABI toolchain, because of its assumpti...

Doom plugin: In anticipation of moving to the EABI toolchain, because of its assumptions about enums being sized as ints, convert enum typdefs to int or unsigned depending upon whether they have negative values in the enumeration. This should effectively preserve the manner in which it is compiled under the old toolchain and avoids having to closely inspect and possibly change many places in the code.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26368 a1c6a512-1295-4272-9138-f99709370657