of/flattree: Merge of_flat_dt_is_compatible

Merge common code between PowerPC and Microblaze

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Tested-by: Michal Simek <monstr@monstr.eu>
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index b17a908..5cdd958 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -142,3 +142,27 @@
 	} while (1);
 }
 
+/**
+ * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
+ * @node: node to test
+ * @compat: compatible string to compare with compatible list.
+ */
+int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
+{
+	const char *cp;
+	unsigned long cplen, l;
+
+	cp = of_get_flat_dt_prop(node, "compatible", &cplen);
+	if (cp == NULL)
+		return 0;
+	while (cplen > 0) {
+		if (strncasecmp(cp, compat, strlen(compat)) == 0)
+			return 1;
+		l = strlen(cp) + 1;
+		cp += l;
+		cplen -= l;
+	}
+
+	return 0;
+}
+