ata: ahci_brcmstb: disable NCQ for MIPS-based platforms

The most MIPS-based platforms need to disable NCQ while have the NCQ
capability in HOST_CAP, and several ARM-based platforms (eg. BCM7349A0,
BCM7445A0, BCM7445B0) need to disable too.

Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Brian Norris <computersforpeace@gmail.com>