ARM: davinci: fix Kconfig for DA850_EVM

The DAVINCI_DA850_EVM board uses an unusual method to
enable the GPIO_PCA953X and KEYBOARD_GPIO_POLLED symbols,
which leads to the dependencies on these symbols being
ignored. As GPIO_PCA953X actually requires I2C, that
can lead to build failures when I2C is disabled.

This patch removes the duplicate symbol definitions
and instead enables them from the davinci_all_defconfig
file.

A different question whether we actually want to automatically
enable them at all or rather put them into defconfig,
but that should be a separate patch.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: davinci-linux-open-source@linux.davincidsp.com