[ARM] pxa/imote2: Fix iMote2 defconfig

- Bring in a CMDLINE that actually works and prints to the right tty
- Compile-in JFFS2 to boot into rootfs
- Remove unneeded options for Bluetooth and radio
- Disable CPU_FREQ as it makes the flash driver fail

Thanks Jonathan for spotting what I messed up.

Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>