MAINTAINERS: Fix a linusw mail address

The patch adding me to the SoC maintainers was in-flight at the
time I had to change my mail address. This fixes it up.

Signed-off-by: Linus Walleij <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Krzysztof Kozlowski <[e-mail]>

MAINTAINERS

···
 M:	Arnd Bergmann <[e-mail]>
 M:	Krzysztof Kozlowski <[e-mail]>
 M:	Alexandre Belloni <[e-mail]>
-M:	Linus Walleij <[e-mail]>
+M:	Linus Walleij <[e-mail]>
 R:	Drew Fustini <[e-mail]>
 L:	[e-mail] (moderated for non-subscribers)
 L:	[e-mail]