buildgcc: Disable RISC-V GDB

Our GDB doesn't support RISC-V yet, so let's disable it for now
to keep the build from breaking.

Change-Id: Iecc6d97fb16d16410c56965abeea55c67800f220
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: https://review.coreboot.org/13872
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
1 file changed