UBUNTU: SAUCE: cxlflash: Read host function configuration

UBUNTU: SAUCE: cxlflash: Read host function configuration

BugLink: http://bugs.launchpad.net/bugs/1752672
Per the OCXL specification, the underlying host can have multiple AFUs
per function with each function supporting its own configuration. The host
function configuration is read on the initialization path to evaluate the
number of functions present and identify the features and configuration of
the functions present. This data is cached for use in later configuration
steps. Note that for the OCXL hardware supported by the cxlflash driver,
only one AFU per function is expected.

Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>