docs: s3tc -> S3TC

Reviewed-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7060>
diff --git a/docs/faq.rst b/docs/faq.rst
index 936f0d1f..6f8bb59 100644
--- a/docs/faq.rst
+++ b/docs/faq.rst
@@ -296,10 +296,10 @@
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 Oh but it is! Prior to 2nd October 2017, the Mesa project did not
-include s3tc support due to intellectual property (IP) and/or patent
-issues around the s3tc algorithm.
+include S3TC support due to intellectual property (IP) and/or patent
+issues around the S3TC algorithm.
 
-As of Mesa 17.3.0, Mesa now officially supports s3tc, as the patent has
+As of Mesa 17.3.0, Mesa now officially supports S3TC, as the patent has
 expired.
 
 In versions prior to this, a 3rd party `plug-in