MAINTAINERS: Remove Liam Mark from DMA-BUF HEAPS FRAMEWORK

@codeaurora.org email addresses are no longer valid and will bounce.

I reached out to Liam about updating his entry under DMA-BUF HEAPS
FRAMEWORK with an @codeaurora.org address.  His response:

"I am not a maintainer anymore, that should be removed."

Liam currently does not have an email address that can be used to remove
this entry, so I offered to submit a cleanup on his behalf with Liam's
consent.

Signed-off-by: Jeffrey Hugo <[email protected]>
Acked-by: John Stultz <[email protected]>
Signed-off-by: Sumit Semwal <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

MAINTAINERS

@@ -6168,7 +6168,6 @@ F:	kernel/dma/
 DMA-BUF HEAPS FRAMEWORK
 M:	Sumit Semwal <[email protected]>
 R:	Benjamin Gaignard <[email protected]>
-R:	Liam Mark <[email protected]>
 R:	Laura Abbott <[email protected]>
 R:	Brian Starkey <[email protected]>
 R:	John Stultz <[email protected]>