HID: make debugging output runtime-configurable

There have been many reports recently about broken HID devices, the
diagnosis of which required users to recompile their kernels in order
to be able to provide debugging output needed for coding a quirk for
a particular device.

This patch makes CONFIG_HID_DEBUG default y if !EMBEDDED and makes it
possible to control debugging output produced by HID code by supplying
'debug=1' module parameter.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>