arm64: renesas: r8a779g3: Reset PCIe before next stage on Retronix R-Car V4H Sparrow...

arm64: renesas: r8a779g3: Reset PCIe before next stage on Retronix R-Car V4H Sparrow Hawk

Fully reset both PCIe controllers before booting the next stage on
Retronix R-Car V4H Sparrow Hawk board. This is necessary especially
in case U-Boot brought up the PCIe controllers, at which point the
next stage might be confused by the state of the PCIe controller.
The reset has to happen this late and not in the PCIe controller
driver, because the SRCR11 bits seem to affect both controllers.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>