MAINTAINERS: wifi: brcm80211: remove non-existing SHA-cyfmac-dev-list@infineon.com

When sending an email to SHA-cyfmac-dev-list@infineon.com, the server
responds '550 #5.1.0 Address rejected.'
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20231218121105.23882-1-lukas.bulwahn@gmail.com

MAINTAINERS

@@ -4138,7 +4138,6 @@ M:	Franky Lin <franky.lin@broadcom.com>
 M:	Hante Meuleman <hante.meuleman@broadcom.com>
 L:	linux-wireless@vger.kernel.org
 L:	brcm80211-dev-list.pdl@broadcom.com
-L:	SHA-cyfmac-dev-list@infineon.com
 S:	Supported
 F:	drivers/net/wireless/broadcom/brcm80211/