MAINTAINERS: update for mwifiex driver maintainers

Amit & Nishant would be taking care of maintaining mwifiex driver here
onwards on account of organizational changes.

Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Nishant Sarmukadam <nishants@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>
Signed-off-by: Frank Huang <frankh@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

MAINTAINERS

@@ -6483,7 +6483,7 @@ F:	drivers/net/ethernet/marvell/mvneta.*
 
 MARVELL MWIFIEX WIRELESS DRIVER
 M:	Amitkumar Karwar <akarwar@marvell.com>
-M:	Avinash Patil <patila@marvell.com>
+M:	Nishant Sarmukadam <nishants@marvell.com>
 L:	linux-wireless@vger.kernel.org
 S:	Maintained
 F:	drivers/net/wireless/mwifiex/