gpio/misc: Add MODULE_ALIAS entries for CS5535 functions

This adds MODULE_ALIAS entries to the various cs5535 subdevice modules; this
allows the modules to automatically be loaded when cs5535-mfd loads.

Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>