DaVinci: DM365: Add the device_enable for the DaVinci Keyscan

Adds the device_enable function to the DaVinci Keyscan platform data
to setup the PINMUX configuration.

It also removes #ifdef from the DM365 EVM board in order to load it
properly as a module.

Signed-off-by: Miguel Aguilar <miguel.aguilar@ridgerun.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>