ar71xx: qca955x pci init/reset fixes

ar71xx: qca955x pci init/reset fixes

Current ar724x code does the reset only on single pci bus, and
in case of qca9558 writes the wrong register (0x10 vs 0x0c).
This change allows the reset of second pci bus, commonly used in
Archer C7 devices, in case host controller is stuck in reset.
If the resetting controller on boot can solve any other issue it
can be enabled unconditionally by removing reset check before
ar724x_pci_hw_init is called.

Signed-off-by: Tomislav Požega <pozega.tomislav@gmail.com>
[refreshed to apply cleanly]
Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
(cherry picked from commit 76d870871cb12fc0c170e5fd23bce568adfaae6d)