Added functions for chip status and chip reset.

[skytee]

Howdy neighbor, I added a function to issue a reset command so the flash chip would reset to single SPI mode and three-byte addressing mode. I also added a function to read the status register, so I know when the SPI flash is done erasing before I write to it again. This has been a nifty tool in my UEFI adventures and I hope you approve. skytee