powerpc/ps3: Update ps3_defconfig

Update ps3_defconfig.

 o Refresh for 2.6.31.
 o Remove MTD support.
 o Add more HID drivers.

Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>