[ARM] 5445/1: AT91: Remove flexible array from USBH platform data

The flexible array in the USBH platform data is not safe to copy.  The
compiler will not allocate any extra memory for the non-init platform
data structure (in the *_devices.c files) since it isn't given any
defaults at compile time.  When the probe function attempts to address
that array, it will actually attempt to access data in an adjacent
structure.

Since there are currently no (known) implementations of the at91 USBH
IP with more than 2 vbus pins, I am capping the value at 2.  If somebody
tries to assign more, then the compiler will produce a warning.

Signed-off-by: Justin Waters <justin.waters@timesys.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>