MIPS: loongson1: set default number of rx and tx queues for stmmac

Set the default number of RX and TX queues due to
the recent changes of stmmac driver.
Otherwise the ethernet will crash once it starts.

Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17452/


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