MIPS: Loongson1B: Modify DEFAULT_MEMSIZE

This patch changes DEFAULT_MEMSIZE to 64MB
which is the memory size of latest EVB.

Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13856/


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