MIPS: Kconfig: Enable microMIPS support for Malta

Add missing microMIPS support to Malta.  Currently the kernel only
enables support for the instruction set for the SEAD-3 board despite the
fact processor features have nothing to do with the board a processor is
installed in.

In this case there is no way to run microMIPS software in a fully
supported way under Linux on QEMU.  QEMU supports the emulation of a
Malta board, but does not emulate SEAD-3.  Linux supports running
microMIPS code on a SEAD-3 board, but hardcodes such support to off on
an emulated Malta board even if the processor selected has the microMIPS
instruction set implemented.

Adding support for the SEAD-3 to QEMU is a major project.  Flipping a
bit in the kernel that shouldn't have been cleared in the first place is
a trivial effort.  Thus the answer is plain...

Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8478/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>