maintainers: fix Ruud's email

Fix Ruud Derwig's email address.

Change-Id: I5711544af9d595741d03114b5883ee55cd6156b0
Signed-off-by: Chuck Jordan <[email protected]>

Author: cjordan44

MAINTAINERS

@@ -60,7 +60,7 @@ Maintainers List (try to look for most precise areas first)
 		-----------------------------------
 
 ARC ARCHITECTURE
-M:	Ruud Derwig <Ruud.Derwig@synopsys.com>
+M:	Ruud Derwig <rderwig@synopsys.com>
 M:	Chuck Jordan <[email protected]>
 M:	Benjamin Walsh <[email protected]>
 S:	Supported