eeepc-laptop: Fix hwmon interface

Creates a name file in the sysfs directory, that
is needed for the libsensors library to work.
Also rename fan1_pwm to pwm1 and scale its value as needed.

This fixes bug #11520:
http://bugzilla.kernel.org/show_bug.cgi?id=11520



Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>