ARM vf610: add compatibilty strings of supported Vybrid SoC's

The Vybrid SoC family (in the kernel known as vf610) is a familiy
of multiple similar SoC's. The VF5xx series comes without secondary
Cortex-M4 core, while the second number VFx1x indicates the presence
of a L2 cache controller.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>