It will take more than 1s when wake up from deep sleep. Most of the
time is spent on outputing information. This patch reduced the deep
sleep latency by:
1. avoid outputing system informaton
2. remove flush cache after DDR restore
3. skip reloading second stage uboot binary when SD boot
Signed-off-by: Tang Yuantian <Yuantian.Tang@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>