ich_descriptors_tool: Fix target specific flags for MinGW/DJGPP

Make target CFLAGS and binary suffix depend on the target OS, not the
host. Always use FLASHROM_CFLAGS for target-specific flags, as the user
shouldn't override them.

Hopefully fixes https://github.com/flashrom/flashrom/issues/149

Change-Id: I0287247512b5576fa3df20c7d8996d51189dac3c
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/72237
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
1 file changed