MIPS: Cavium: Remove dead CONFIG_GDB_CONSOLE

CONFIG_GDB_CONSOLE doesn't exist in Kconfig, therefore removing all
references for it from the source code.

Signed-off-by: Christoph Egger <siccegge@cs.fau.de>
To: David Daney <ddaney@caviumnetworks.com>
To: Yang Shi <yang.shi@windriver.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
To: Tejun Heo <tj@kernel.org>
To: linux-mips@linux-mips.org
To: linux-kernel@vger.kernel.org
Cc: vamos@i4.informatik.uni-erlangen.de
Patchwork: https://patchwork.linux-mips.org/patch/1368/


Acked-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>