WDR4900v1 remove dt node for absent hw crypto.

The WDR4900v1 uses the P1040 SoC, so the device tree pulls in the
definition for the related P1010 SoC.  However, the P1040 lacks the
CAAM/SEC4 hardware crypto accelerator which the P1010 device tree
defines.  If left defined, this causes the CAAM drivers (if present) to
attempt to use the non-existent device, making various crypto-related
operations (e.g. macsec and ipsec) fail.

This commit overrides the incorrect dt node definition in the included
file.

See also:
 - https://bugs.openwrt.org/index.php?do=details&task_id=1262
 - https://community.nxp.com/thread/338432#comment-474107

Signed-off-by: Tim Small <tim@seoss.co.uk>

target/linux/mpc85xx/files/arch/powerpc/boot/dts/tl-wdr4900-v1.dts

@@ -236,3 +236,27 @@
 };
 
 /include/ "fsl/p1010si-post.dtsi"
+
+/*
+ * The TL-WDR4900 v1 uses the NXP (Freescale) P1014 SoC which is closely
+ * related to the P1010.
+ *
+ * NXP QP1010FS.pdf "QorIQ P1010 and P1014 Communications Processors"
+ * datasheet states that the P1014 does not include the accelerated crypto
+ * module (CAAM/SEC4) which is present in the P1010.
+ *
+ * NXP Appliation Note AN4938 Rev. 2 implies that some P1014 may contain the
+ * SEC4 module, but states that SoCs with System Version Register values
+ * 0x80F10110 or 0x80F10120 do not have the security feature.
+ *
+ * All v1.3 TL-WDR4900 tested have SVR == 0x80F10110 which AN4938 describes
+ * as: core rev 1.0, "P1014 (without security)".
+ *
+ * The SVR value is reported by uboot on the serial console.
+ */
+
+/ {
+	soc: soc@ffe00000 {
+		/delete-node/ crypto@30000; /* Pulled in by p1010si-post */
+	};
+};