[PATCH v5 3/3] ahci_platforms: add support for CNS3xxx SoC devices

From: Mac Lin <redacted>

CNS3xxx override the softreset function of ahci_platform
ahci_softreset by cns3xxx_ahci_softreset, which would retry
ahci_do_softreset again with pmp=0 if
pmp=15 failed, for the controller has problem receiving D2H
Reg FIS of the different PMP setting of the previous sent H2D Reg FIS.

Is this issue only with your ahci platform controller? I came across another 
thread here,

http://www.spinics.net/lists/linux-ide/msg39865.html  

Also, the ahci platform controller on Texas Instruments OMAP L138 platform 
behaves in a similar fashion. 

Currently I see only Cavium Networks, Faraday and TI using ahci platform 
controller and all 3 facing same issue.

Hence, should we fix this in ahci_platform.c conditionally using platform data, 
otherwise we will end-up adding file for every platform (just for one 
function). 

Thanks
Mansoor Ahamed