MIPS: lantiq: Enable AHB Bus for USB

MIPS: lantiq: Enable AHB Bus for USB

On Danube and AR9 the USB core is connected though a AHB bus to the main
system cross bar, hence we need to enable the gating clock of the AHB
Bus as well to make the USB controller work.

Fixes: dea54fbad332 ("phy: Add an USB PHY driver for the Lantiq SoCs using the RCU module")
Signed-off-by: Mathias Kresin <[email protected]>
Signed-off-by: Hauke Mehrtens <[email protected]>
Acked-by: Martin Blumenstingl <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: John Crispin <[email protected]>
Cc: [email protected]
Cc: <[email protected]> # 4.14+
Patchwork: https://patchwork.linux-mips.org/patch/18814/
Signed-off-by: James Hogan <[email protected]>