problem on 85xx/QoirQ platforms

For FSL PPC SoCs USB_ARCH_HAS_EHCI currently on depends on PPC_83xx.
However that excludes support for USB on 85xx & QorIQ devices.  Use
FSL_SOC insted which will get us 83xx, 85xx, QorIQ, and 5xxx which all
have the same USB IP on them.

Signed-off-by: Xulei <B33228@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>