arm64: dts: r8a7795: salvator-x: enable USB 2.0 Host channel 0

We have to set SW15 to pin 2-3 side on the board before we use CN9
as USB host or peripheral.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>