ARM: mxs_defconfig: Remove unneeded options

Remove the following unneeded config options:

- CONFIG_ARM_THUMB is selected by default

- CONFIG_I2C is selected by default.

- CONFIG_FRAMEBUFFER_CONSOLE is selected by default

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>