ls102xa: pblimage: Add pblimage tool support for LS102xA

ls102xa: pblimage: Add pblimage tool support for LS102xA

For LS102xA, the size of spl/u-boot-spl.bin is variable.
This patch adds the support to deal with the variable
u-boot size in pblimage tool. It will be padded to 64
byte boundary.

Use pblimage_check_params() to add the specific operations
for ARM, such as PBI CRC and END command and the calculation
of pbl_cmd_initaddr.

Signed-off-by: Alison Wang <alison.wang@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>