ARM: mmp2: update mmp2_defconfig to support mmc

1. support brownstone
2. support mmc
3. support basic filesystem and language
4. remove dynamic_debug, since too many log during access sd

Signed-off-by: Zhangfei Gao <zhangfei.gao@marvell.com>
Acked-by: Philip Rakity <prakity@marvell.com>
Acked-by: Mark F. Brown <mark.brown314@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>