cros_ec: Split cros_ec_devs module

cros_ec: Split cros_ec_devs module

This patch splits the cros_ec_devs module in two parts with a
cros_ec_dev module responsible for handling MFD devices registration and
a cros_ec_ctl module responsible for handling the various user-space
interfaces.

For consistency purpose, the driver name for the cros_ec_dev module is
now cros-ec-dev instead of cros-ec-ctl.

In the next commit, the new cros_ec_dev module will be moved to the MFD
subtree so mfd_add_devices() calls are not done from outside MFD.

Signed-off-by: Thierry Escande <[email protected]>
Reviewed-by: Gwendal Grignou <[email protected]>
Tested-by: Guenter Roeck <[email protected]>
Signed-off-by: Lee Jones <[email protected]>