mmc: sh_mobile_sdhi: remove support for sh7372

Remove documentation of support for the SH7372 (SH-Mobile AP4) from the MMC
driver. The driver itself appears to have no SH7372 specific code.

Commit edf41009 ("ARM: shmobile: sh7372 dtsi: Remove Legacy file")
removes this SoC from the kernel in v4.1.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/tmio_mmc.txt

@@ -11,7 +11,6 @@ optional bindings can be used.
 
 Required properties:
 - compatible:	"renesas,sdhi-shmobile" - a generic sh-mobile SDHI unit
-		"renesas,sdhi-sh7372" - SDHI IP on SH7372 SoC
 		"renesas,sdhi-sh73a0" - SDHI IP on SH73A0 SoC
 		"renesas,sdhi-r7s72100" - SDHI IP on R7S72100 SoC
 		"renesas,sdhi-r8a73a4" - SDHI IP on R8A73A4 SoC