Hello Amit,
Two points...
In the schematics for the Flash I noted the P1 connector pin-outs are opposite to the X11 connector on the EK. In other words the odd and even sides are swapped.
In the software example you are using EPI0S0, EPI0S1 etc. while in the schematic it is EPIOS0, EPIOS1 etc.
Regards,
Victor