mtd: m25p80: Add support for ESMT F25L32PA

This flashchip is used in D-Link DIR-610 A1 router board
and maybe several others, yet is not kernel upstream.

So add support for it according to datasheet [0], making it easier
to support other boards using this flashchip in the future.

[0] http://www.esmt.com.tw/DB/manager/upload/F25L32PA.pdf



Signed-off-by: Flavio Silveira <fggs@terra.com.br>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>