Remove forward function declarations in this driver.  Also move some
constant structure definitions lower in the file.  There are no changes to
the code that has been moved.

Link: https://lore.kernel.org/r/20220725151258.42574-2-jim2101024@gmail.comSigned-off-by: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>