vdin: fixed the issue of mem mapping from vmap. [1/1]

vdin: fixed the issue of mem mapping from vmap. [1/1]

PD#SWPL-6196

Problem:
the memory issue cause to kernel crash.

Solution:
1. add flush cache when the mem oper end.
2. unmap addr which from vmap in vdin driver.

Verify:
X301

Change-Id: Id6efe2b009fe64ad753d51eb06784bd4e66f5e87
Signed-off-by: Nanxin Qin <nanxin.qin@amlogic.com>