vlynq: remove bus driver

There are no users with a vlynq_driver in the Kernel tree. Also, only
the AR7 platform ever initialized a VLYNQ bus, but AR7 is going to be
removed from the Kernel. OpenWRT had some out-of-tree drivers which they
probably intended to upport, but AR7 devices are even there not
supported anymore because they are "stuck with Kernel
3.18" [1]. This code can go.

[1] https://openwrt.org/docs/techref/targets/ar7



Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>