MAINTAINERS: Add Sven Peter as ARM/APPLE MACHINE maintainer

Hector suggested I should add myself to help him maintain the
platform.
Acked-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Sven Peter <sven@svenpeter.dev>

MAINTAINERS

@@ -1712,6 +1712,7 @@ F:	drivers/*/*alpine*
 
 ARM/APPLE MACHINE SUPPORT
 M:	Hector Martin <marcan@marcan.st>
+M:	Sven Peter <sven@svenpeter.dev>
 R:	Alyssa Rosenzweig <alyssa@rosenzweig.io>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained