This adds support for describing GPIO chips placed on PCIe cards. Thanks
to this we get working 2.4 GHz LED on Tenda AC9.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
It adds and uses ILP clock that requires some other work (in progress)
for upstreaming it. Other than that it adds a quick fix for bcma to add
serial flash before trying to read SPROM.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>