MA-16457-4 fix issue of evk_7ulp using boot-debug.img

MA-16457-4 fix issue of evk_7ulp using boot-debug.img

evk_7ulp has recovery partition, the ramdisk in boot.img and
boot-debug.img is normal boot ramdisk not recovery ramdisk, in this
condition, there is no need to pass the bootargs to indicate it's to
boot up to Android or recovery.

Change-Id: Ic3e04aaf361b78e36c95d19f87dc266bf9b6c7d6
Signed-off-by: faqiang.zhu <faqiang.zhu@nxp.com>
(cherry picked from commit 6e0dec768a2d16a6ff2de31fbd319d045ac83c48)
(cherry picked from commit 59abb5e52b70df34d415031d4b89606c7543b999)