MIPS: Octeon: Select CONFIG_HOLES_IN_ZONE

MIPS: Octeon: Select CONFIG_HOLES_IN_ZONE

Current Octeon systems do in fact have holes in their memory zones.
We need to select HOLES_IN_ZONE.  If we do not, some memory
configurations will result in crashes at boot time like this:

.
.
.
CPU 6 Unable to handle kernel paging request at virtual address 0000000000700000, epc == ffffffff8118fe00, ra == ffffffff8118fe9c
Oops[#1]:
Cpu 6
.
.
.
        ...
Call Trace:
[<ffffffff8118fe00>] setup_per_zone_wmarks+0x1b0/0x338
[<ffffffff815cd738>] init_per_zone_wmark_min+0x64/0xd0
[<ffffffff81100438>] do_one_initcall+0x38/0x160
.
.
.

Reported-by: Jason Kwon <jason.kwon@ericsson.com>
Signed-off-by: David Daney <david.daney@cavium.com>
To: linux-mips@linux-mips.org
Cc: Jason Kwon <jason.kwon@ericsson.com>
Patchwork: https://patchwork.linux-mips.org/patch/2724/
Tested-by: Guenter Roeck<guenter.roeck@ericsson.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>