Adesto AT25SF041(formerly atmel) with chip erase

[mrbell321]

I'm adding support for AT25SF041 which is an Adesto product. Formerly Atmel. We you prefer this under the AT25 heading since it's not officially Atmel? Or create a new class for Adesto?
I'm also working with Winbond W25X4 and both chips support chip_erase, but I"m not immediately seeing a clean way to implement this with the existing structure. It's a different command w/ different parameters and operating requirements. I have added a separate 'erase_chip' method as a POC, but if you have any ideas on how to integrate this into the existing erase() methods, I'm all ears.