DT: bindings: remove bcm2835-sdhci

The sdhci-iproc also supports bcm2835. So this binding is obsolete.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/brcm,bcm2835-sdhci.txt

-Broadcom BCM2835 SDHCI controller
-
-This file documents differences between the core properties described
-by mmc.txt and the properties that represent the BCM2835 controller.
-
-Required properties:
-- compatible : Should be "brcm,bcm2835-sdhci".
-- clocks : The clock feeding the SDHCI controller.
-
-Example:
-
-sdhci: sdhci {
-	compatible = "brcm,bcm2835-sdhci";
-	reg = <0x7e300000 0x100>;
-	interrupts = <2 30>;
-	clocks = <&clk_mmc>;
-	bus-width = <4>;
-};