ARM: defconfig: pxa: cut MPU3050 input driver

The PXA defconfig compiles the legacy MPU3050 driver as a module,
but the device does not appear in device trees nor board files, so
remove this from the defconfig assuming it was a mistake to add it
in the first place.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>