MAINTAINERS: update Kalle Valo's email

I switched to using [e-mail], update MAINTAINERS file.

Signed-off-by: Kalle Valo <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

MAINTAINERS

···
 F:	drivers/phy/qualcomm/phy-ath79-usb.c
 
 ATHEROS ATH GENERIC UTILITIES
-M:	Kalle Valo <[e-mail]>
+M:	Kalle Valo <[e-mail]>
 L:	[e-mail]
 S:	Supported
 F:	drivers/net/wireless/ath/*
···
 F:	drivers/net/wireless/ath/ath5k/
 
 ATHEROS ATH6KL WIRELESS DRIVER
-M:	Kalle Valo <[e-mail]>
+M:	Kalle Valo <[e-mail]>
 L:	[e-mail]
 S:	Supported
 W:	https://wireless.wiki.kernel.org/en/users/Drivers/ath6kl
···
 F:	include/uapi/linux/netdevice.h
 
 NETWORKING DRIVERS (WIRELESS)
-M:	Kalle Valo <[e-mail]>
+M:	Kalle Valo <[e-mail]>
 L:	[e-mail]
 S:	Maintained
 Q:	http://patchwork.kernel.org/project/linux-wireless/list/
···
 F:	drivers/media/tuners/qt1010*
 
 QUALCOMM ATHEROS ATH10K WIRELESS DRIVER
-M:	Kalle Valo <[e-mail]>
+M:	Kalle Valo <[e-mail]>
 L:	[e-mail]
 S:	Supported
 W:	https://wireless.wiki.kernel.org/en/users/Drivers/ath10k
···
 F:	drivers/net/wireless/ath/ath10k/
 
 QUALCOMM ATHEROS ATH11K WIRELESS DRIVER
-M:	Kalle Valo <[e-mail]>
+M:	Kalle Valo <[e-mail]>
 L:	[e-mail]
 S:	Supported
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git
···
 F:	drivers/media/platform/qcom/venus/
 
 QUALCOMM WCN36XX WIRELESS DRIVER
-M:	Kalle Valo <[e-mail]>
+M:	Kalle Valo <[e-mail]>
 L:	[e-mail]
 S:	Supported
 W:	https://wireless.wiki.kernel.org/en/users/Drivers/wcn36xx