arm64: dts: r8a7796: salvator-x: enable UHS for SDHI 0 & 3

Based on work for the r8a7796 by Wolfram Sang.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>