need help in changing the deay in SYSRESET block in Igloo-2 device implementation

I haven't used VHDL in a long time but if that delay is stored as a generic (I think that's what VHDL calls parameters) then when you instantiate their block you should be able to set the generic to whatever you want. If that value is actually a delay and not synthesizeable it won't matter what you set it to, and given the IP is encrypted the only way to find out what it implements is through trial and error I guess. If you are stuck for more than 30 minutes I recommend just looking around for a reset deglitch block from somewhere, there has to be thousands of them only a google search away that are plain text and not encrypted.