lima: renderonly: import dumb buffer from kms driver

Created by: enunes

This patch modifies the renderonly implementation to allocate a dumb buffer for scanout in the kms driver and import it in lima. In contrast, the previous renderonly implementation allocated a contiguous buffer in lima and exported to the kms driver. As stated in Issue #29 (closed), changing this around is useful to lima because lima currently supports the contiguous allocation method mostly to satisfy the requirement of exporting a scanout buffer to a kms display driver (which may not support non-contiguous buffers). So with this change, the contiguous allocation method may be dropped in the future to reduce the complexity of the memory allocation in lima.

Signed-off-by: Erico Nunes nunes.erico@gmail.com