HID: merge hid-egalax into hid-multitouch

This patch merges the hid-egalax driver into hid-multitouch.  There
are two types of devices support by the hid-egalax driver: resistive
and capacitive. Here, they are implicitly distinguished by the absence
of a HID_DG_CONTACTCOUNT field in the latter, so no special code path
needs to be introduced.

As a side effect, this patch fixes the broken suspend/resume behavior
in the old driver.

[rydberg@euromail.se: minor fixups]
Signed-off-by: Richard Nauber <Richard.Nauber@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>