sata_rcar: Document deprecated "renesas,rcar-sata"
sata_rcar: Document deprecated "renesas,rcar-sata"

Commit e67adb4e669db834 ("sata_rcar: Add R-Car Gen2 SATA PHY support")
deprecated "renesas,rcar-sata" in favor of "renesas,sata-r8a7779", but
the deprecated value was never documented in the binding documentation,
while it is still in active use.

Signed-off-by: Geert Uytterhoeven <a1ff81395f7e6bf5b509fe9aab06bf3419493e1d@glider.be>
Acked-by: Simon Horman <9662bddcc379be37df16f02a449c344b4718c1a1@verge.net.au>
Signed-off-by: Tejun Heo <546b05909706652891a87f7bfe385ae147f61f91@kernel.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs