PsramController, FREQ, and INIT_TIME

[edanuff]

I've been playing with your version of the PsramController in another project and found something interesting while testing. The controller appears to work at 100Mhz (100.286Mhz to be exact) using the original psram_test_top.v as long as I keep the value of FREQ at 96000000. At first I thought it just wasn't able to clock at 100Mhz but then realized that the clock speed is coming from the PLL which I'm not changing in my tests and that changing FREQ in the code has no effect other than to change the length of the initialization delay. It's not clear why this is occuring but reporting it as an issue in case you have some thoughts. Thanks for the work on this!