channels available
- current code treats bits 4:7 in 'SATAHC interrupt mask' and 'SATAHC
interrupt cause' as flags for SATA channels 2 and 3
- for embedded SATA controllers (SoC) these bits have been marked as reserved
in datasheets so far, but for some new and upcoming chips they are used for
purposes other than SATA
Submitted by: Lukasz Plachno
Reviewed by: mav
Obtained from: Semihalf
MFC after: 2 weeks