[flashrom] [Patch] Add FEATURE_WRSR_WREN to feature_bits for most AMIC SPI flash chips

[David Hendricks]

This patch adds FEATURE_WRSR_WREN to the feature bits for most AMIC SPI
flash chips. I was unable to find datasheets for all of the chips, but the
datasheets presently on http://www.amictechnology.com/ indicate that the SPI
flash chips use WREN.

Signed-off-by: David Hendricks