kgsl/drm: Change dma_buf api

This patch chagnes dma_buf api. ion api was changed.

Change-Id: I27bef649f5964cbdd449c9e9ca5c57d0fc8cc611
Signed-off-by: Eunchul Kim <chulspro.kim@samsung.com>
Signed-off-by: Taeheon Kim <th908.kim@samsung.com>
Signed-off-by: Mathew Karimpanal <kjmathew@codeaurora.org>
(cherry picked from commit 34f084f1036a78592eb01b55e9e91f9dc89be7b3)
[lvaz@codeaurora.org: typecast the return value of
 ion_share_dma_buf_fd() to int]
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>