MAINTAINERS: update for mwifiex driver maintainers

Add Sharvari Harisangam to Maintainer list.
Replace Ganapathi Bhat's email id in Maintainer list.

Signed-off-by: Rakesh Parmar <rakesh.parmar@nxp.com>
Signed-off-by: Sharvari Harisangam <sharvari.harisangam@nxp.com>
Acked-by: Ganapathi Bhat <ganapathi.bhat@nxp.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1613998184-20047-1-git-send-email-sharvari.harisangam@nxp.com