MAINTAINERS: Update the entry for MHI bus

Since Hemant is not carrying out any maintainership duties let's make
him as a dedicated reviewer. Also add the new mailing lists dedicated
for MHI in subspace mailing list server.

Reviewed-by: Hemant Kumar <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

MAINTAINERS

@@ -12214,7 +12214,8 @@ F:	arch/arm64/boot/dts/marvell/armada-3720-uDPU.dts
 
 MHI BUS
 M:	Manivannan Sadhasivam <[email protected]>
-M:	Hemant Kumar <[email protected]>
+R:	Hemant Kumar <[email protected]>
+L:	[email protected]
 L:	[email protected]
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mani/mhi.git