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-v2014.10.rst b/doc/develop/statistics/u-boot-stats-v2014.10.rst
index ef33126..b5c794a 100644
--- a/doc/develop/statistics/u-boot-stats-v2014.10.rst
+++ b/doc/develop/statistics/u-boot-stats-v2014.10.rst
@@ -3,7 +3,7 @@
 Release Statistics for U-Boot v2014.10
 ======================================
 
-* Processed 1111 csets from 145 developers
+* Processed 1111 changesets from 145 developers
 
 * 24 employers found