Move e.g. backlight_init() and backlight_exit() together along with the
other backlight functions, instead of grouping init() and exit()
functions.  Move e.g. backlight_ops to follow the functions it refers
to, and remove the forward declarations.  The code itself should remain
unchanged.

The eeepc-laptop driver implements a number of interfaces like the
backlight class driver.  This change makes it easier to examine the
implementation of one interface at at a time, without having to search
through the file to find init() and exit() functions etc.
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Len Brown <len.brown@intel.com>