staging: ccree: remove interim DT docs

As proper DT bindings doc where submitted and ACKed,
remove the interim one.
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ccree/Documentation/devicetree/bindings/crypto/arm-cryptocell.txt

-Arm TrustZone CryptoCell cryptographic accelerators
-
-Required properties:
-- compatible: must be "arm,cryptocell-712-ree".
-- reg: shall contain base register location and length.
-	Typically length is 0x10000.
-- interrupts: shall contain the interrupt for the device.
-
-Optional properties:
-- interrupt-parent: can designate the interrupt controller the
-	device interrupt is connected to, if needed.
-- clocks: may contain the clock handling the device, if needed.
-- power-domains: may contain a reference to the PM domain, if applicable.
-
-
-Examples:
-
-Zynq FPGA device
-----------------
-
-       arm_cc7x: arm_cc7x@80000000 {
-               compatible = "arm,cryptocell-712-ree";
-               interrupt-parent = <&intc>;
-               interrupts = < 0 30 4 >;
-               reg = < 0x80000000 0x10000 >;
-       };
-