Add AX88772B ID together with two fixes needed to make this work.

1. The packet length check has to be adjusted, as all ASIX chips
only use 11 bits to indicate the length. AX88772B uses the other
bits to indicate unrelated things, which cause the check to fail.
This fix is based on a fix for the Linux kernel by Marek Vasut.
Linux upstream commit: bca0beb9363f8487ac902931a50eb00180a2d14a

2. AX88772B provides several bulk endpoints. Only the first
IN/OUT endpoints work in the default configuration. So stop
enumeration after we found them to avoid overwriting the
endpoint config with a non-working one.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Reviewed-by: Marek Vasut <marex@denx.de>
Acked-by: Marek Vasut <marex@denx.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>