[ARM] 5579/1: Updated U300 defconfig

This defconfig update selects all the new U300 drivers merged for
2.6.31-rc1 in the merge window and add defaults for the new
config options. It compiles and boots nicely from initramfs on
the U300.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>