ahci: factor out AHCI enabling and enable AHCI before reading CAP
ahci: factor out AHCI enabling and enable AHCI before reading CAP

Factor out AHCI enabling into ahci_enable_ahci() and enabling AHCI
before reading CAP in ahci_save_initial_config() as the spec requires
enabling AHCI mode before accessing any other registers.

Signed-off-by: Tejun Heo <ccfba69985e72fbcd9ba8bbb6db43d42971ad06d@gmail.com>
Signed-off-by: Jeff Garzik <f3e731dfa293c7a83119d8aacfa41b5d2d780be9@garzik.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas