staging: most: rename struct most_aim

The designator of a module that proivdes means to interface userspace is
called an AIM. Since this name seems to be unappropiate, this kind of
moduels are going to be referred to as componetns. This is done because
such modules function as components to enhance the core with new features.
This patch renames the struct most_aim to core_component.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>