ANDROID: dma-buf: Add vendorhook to allow mmaping more memory than a DMA-BUF holds

Add vendorhook to allow mmaping more memory than a DMA-BUF holds. The
implementor of the vmap callback for the DMA-BUF is responsible for
ensuring that all pages are backed by memory. The hook takes as input
a DMA-BUF to allow the VMA bounds check to be done on a case-by-case
basis for DMA-BUFs.

Note that if the override is allowed to go through for a given
DMA-BUF, then it can be the case that the size of this mmaped DMA-BUF
is reported incorrectly when looking at /proc/pid/maps for the owning
process.

Bug: 234753494
Change-Id: Iba8cc8adfd2290e4dc7ef04fce5d6a80ac92e0b3
Signed-off-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
Signed-off-by: Sukadev Bhattiprolu <quic_sukadev@quicinc.com>