staging: dgap: removes proc.c

This patch removes proc.c. This code isn't needed anymore because
a previous patch removed references to it and because the kernel
uses sysfs instead of proc.

Signed-off-by: Lidza Louina <lidza.louina@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>