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-v2008.10.rst b/doc/develop/statistics/u-boot-stats-v2008.10.rst
index b163a5c..0370c70 100644
--- a/doc/develop/statistics/u-boot-stats-v2008.10.rst
+++ b/doc/develop/statistics/u-boot-stats-v2008.10.rst
@@ -3,7 +3,7 @@
 Release Statistics for U-Boot v2008.10
 ======================================
 
-* Processed 2498 csets from 174 developers
+* Processed 2498 changesets from 174 developers
 
 * 85 employers found