doc: process: GPL -> GPL-compatible

Drivers under MIT, BSD-17-clause, or uncle-Bob's-newest-take-on-PD are
all fine, not just GPL.

Signed-off-by: Adam Borowski <[e-mail]>
[jc: fixed conflict and refilled paragraph]
Reviewed-by: Greg Kroah-Hartman <[e-mail]>
Signed-off-by: Jonathan Corbet <[e-mail]>

Documentation/process/stable-api-nonsense.rst

···
 nightmare, and trying to keep up with an ever changing kernel interface
 is also a rough job.
 
-Simple, get your kernel driver into the main kernel tree (remember we
-are talking about GPL released drivers here, if your code doesn't fall
-under this category, good luck, you are on your own here, you leech).  If your
-driver is in the tree, and a kernel interface changes, it will be fixed
-up by the person who did the kernel change in the first place.  This
-ensures that your driver is always buildable, and works over time, with
-very little effort on your part.
+Simple, get your kernel driver into the main kernel tree (remember we are
+talking about drivers released under a GPL-compatible license here, if your
+code doesn't fall under this category, good luck, you are on your own here,
+you leech).  If your driver is in the tree, and a kernel interface changes,
+it will be fixed up by the person who did the kernel change in the first
+place.  This ensures that your driver is always buildable, and works over
+time, with very little effort on your part.
 
 The very good side effects of having your driver in the main kernel tree
 are: