ENGR00259607 MXC V4L2 output:Replace classical timer with hrtimer

This patch replaces the old classical timer(low resolution timer)
with high resolution timer. This change improves the accuracy of
time point we put/activate buffers on display flow. For example,
we intend to show several frames in a framerate of 30fps(constant
interval bewteen 2 adjacent frames should be 33.33ms), the classical
timer would introduce a 10ms error in the interval which may
downgrade the video quality(jitter can be seen).

Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
ENGR00239571: [MX28]audio playback can't go on after resume from mem mode.

mxs-saif driver need backup SAIF registers when enter suspend
and restore SAIF registers when resume,pcm driver need restart
DMA when resume to continue playback.

Signed-off-by: Grace Si <b18730@freescale.com>
ENGR00260707 Update the MX28 defconfig

Enable DEV_TMPFS to support the udev included in Yocto
Enable NFS_V4 to support new host distributions
Cleared the UEVENT_HELPER_PATH as this not used.

Signed-off-by: Mahesh Mahadevan <Mahesh.Mahadevan@freescale.com>