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@codeaurora.org email addresses are no longer valid and will bounce.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 <quic_jhugo@quicinc.com>
Acked-by: John Stultz <jstultz@google.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230628180534.31819-1-quic_jhugo@quicinc.com