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-v2010.03.rst b/doc/develop/statistics/u-boot-stats-v2010.03.rst
index 15b5741..5a8b0d6 100644
--- a/doc/develop/statistics/u-boot-stats-v2010.03.rst
+++ b/doc/develop/statistics/u-boot-stats-v2010.03.rst
@@ -3,7 +3,7 @@
 Release Statistics for U-Boot v2010.03
 ======================================
 
-* Processed 468 csets from 92 developers
+* Processed 468 changesets from 92 developers
 
 * 29 employers found