PATCH: Adding support for Sanyo "LE25FU206"

[The_Raven Raven]

Hi

I made a Patch for adding Sanyo "LE25FU206" Chip.

Tested (with raspberrypi-linux_spi):
- Probing
- Reading (i readed the chip 3 times and make a diff, all diffs are same)
- Erasing (tested all 3 erase-modes)
- Writing data1
- Writing data2 (overwriting)

Greets