hwrng: xgene - add ACPI support for APM X-Gene RNG unit

This adds ACPI support for APM X-Gene RNG unit.
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/xgene-rng.c

@@ -21,6 +21,7 @@
  *
  */
 
+#include <linux/acpi.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/hw_random.h>
@@ -310,6 +311,14 @@ static int xgene_rng_init(struct hwrng *rng)
 	return 0;
 }
 
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id xgene_rng_acpi_match[] = {
+	{ "APMC0D18", },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, xgene_rng_acpi_match);
+#endif
+
 static struct hwrng xgene_rng_func = {
 	.name		= "xgene-rng",
 	.init		= xgene_rng_init,
@@ -415,6 +424,7 @@ static struct platform_driver xgene_rng_driver = {
 	.driver = {
 		.name		= "xgene-rng",
 		.of_match_table = xgene_rng_of_match,
+		.acpi_match_table = ACPI_PTR(xgene_rng_acpi_match),
 	},
 };