README: Fix a typo

Fix the spelling of "regarding".

Signed-off-by: Fabio Estevam <festevam@gmail.com>

README

@@ -83,7 +83,7 @@ Stefano Babic <sbabic@denx.de>
 Submitting patches
 ------------------
 
-You can submit your patches (or post questions reagarding
+You can submit your patches (or post questions regarding
 this layer to the swupdate Mailing List:
 
 	swupdate@googlegroups.com