Attach the S2-only secure camera preview buffers with dummy drm
device during dma_buf_attach. This will ensure when sg_dma_address
will return the phys address for this buffer as its not backed
by a context-bank.
Change-Id: Iafd40352b92b842d19194976fa4b58e1e07e6f0d
Signed-off-by: Veera Sundaram Sankaran <quic_veeras@quicinc.com>