Documentation/bindings: crypto: document the SafeXcel EIP97 compatible

This patch adds the SafeXcel EIP97 compatible to the Inside Secure
device tree bindings documentation.
Signed-off-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Documentation/devicetree/bindings/crypto/inside-secure-safexcel.txt

 Inside Secure SafeXcel cryptographic engine
 
 Required properties:
-- compatible: Should be "inside-secure,safexcel-eip197".
+- compatible: Should be "inside-secure,safexcel-eip197" or
+              "inside-secure,safexcel-eip97".
 - reg: Base physical address of the engine and length of memory mapped region.
 - interrupts: Interrupt numbers for the rings and engine.
 - interrupt-names: Should be "ring0", "ring1", "ring2", "ring3", "eip", "mem".