doc: Use "changesets" not "csets" in statistics pages

To make things more human readable, say "changesets from" rather than
"csets from" in all our historical pages here. Moving forward this has
been changed in our gitdm with b034e399e31a ("gitdm: fix typo csets").

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/doc/develop/statistics/u-boot-stats-v2022.07.rst b/doc/develop/statistics/u-boot-stats-v2022.07.rst
index c1b627c..dc54e9a 100644
--- a/doc/develop/statistics/u-boot-stats-v2022.07.rst
+++ b/doc/develop/statistics/u-boot-stats-v2022.07.rst
@@ -3,7 +3,7 @@
 Release Statistics for U-Boot v2022.07
 ======================================
 
-* Processed 1696 csets from 183 developers
+* Processed 1696 changesets from 183 developers
 
 * 27 employers found