[media] v4l: Remove V4L2_BUF_FLAG_EOS

Complete the renaming process of V4L2_BUF_FLAG_EOS to
V4L2_QCOM_BUF_FLAG_EOS.

Also change the value of *_EOS to 0x1000000 as to not
conflict with standard specific defines.

Change-Id: I68162a57d902c25757e071854f2770d2eb4bb740
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>