a10: add pcduino.fex from the stock evb.bin

Contributed-by: digitalhack <digitalhack17@gmail.com>
Signed-off-by: Alejandro Mery <amery@geeks.cl>
pcduino: fix dram_para based on a10-meminfo

Thanks to digialhack

Signed-off-by: Alejandro Mery <amery@geeks.cl>