dt-bindings: clock: add rk3399 DDR3 standard speed bins.

DDR3 SDRAM Standard (JESD79-3F) defines some standard speed bins for
DDR3 memories. The rk3399_dmc driver allows you to pass these values via
the device tree. For that purpose the devfreq/rk3399_dmc.txt binding
refers to a ddr.h file which does not exist. This patch adds the missing
defines in a include file called rk3399-ddr.h with the definition of
standard speed bins according to the ARM Trusted Firmware (ATF).

Fixes: c1ceb8f7c167 (Documentation: bindings: add dt documentation for rk3399 dmc)
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt

@@ -19,7 +19,7 @@ Required properties:
 
 Following properties relate to DDR timing:
 
-- rockchip,dram_speed_bin :	  Value reference include/dt-bindings/clock/ddr.h,
+- rockchip,dram_speed_bin :	  Value reference include/dt-bindings/clock/rk3399-ddr.h,
 				  it selects the DDR3 cl-trp-trcd type. It must be
 				  set according to "Speed Bin" in DDR3 datasheet,
 				  DO NOT use a smaller "Speed Bin" than specified

include/dt-bindings/clock/rk3399-ddr.h

@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR MIT) */
+
+#ifndef DT_BINDINGS_DDR_H
+#define DT_BINDINGS_DDR_H
+
+/*
+ * DDR3 SDRAM Standard Speed Bins include tCK, tRCD, tRP, tRAS and tRC for
+ * each corresponding bin.
+ */
+
+/* DDR3-800 (5-5-5) */
+#define DDR3_800D	0
+/* DDR3-800 (6-6-6) */
+#define DDR3_800E	1
+/* DDR3-1066 (6-6-6) */
+#define DDR3_1066E	2
+/* DDR3-1066 (7-7-7) */
+#define DDR3_1066F	3
+/* DDR3-1066 (8-8-8) */
+#define DDR3_1066G	4
+/* DDR3-1333 (7-7-7) */
+#define DDR3_1333F	5
+/* DDR3-1333 (8-8-8) */
+#define DDR3_1333G	6
+/* DDR3-1333 (9-9-9) */
+#define DDR3_1333H	7
+/* DDR3-1333 (10-10-10) */
+#define DDR3_1333J 	8
+/* DDR3-1600 (8-8-8) */
+#define DDR3_1600G	9
+/* DDR3-1600 (9-9-9) */
+#define DDR3_1600H	10
+/* DDR3-1600 (10-10-10) */
+#define DDR3_1600J	11
+/* DDR3-1600 (11-11-11) */
+#define DDR3_1600K	12
+/* DDR3-1600 (10-10-10) */
+#define DDR3_1866J	13
+/* DDR3-1866 (11-11-11) */
+#define DDR3_1866K	14
+/* DDR3-1866 (12-12-12) */
+#define DDR3_1866L	15
+/* DDR3-1866 (13-13-13) */
+#define DDR3_1866M	16
+/* DDR3-2133 (11-11-11) */
+#define DDR3_2133K	17
+/* DDR3-2133 (12-12-12) */
+#define DDR3_2133L	18
+/* DDR3-2133 (13-13-13) */
+#define DDR3_2133M	19
+/* DDR3-2133 (14-14-14) */
+#define DDR3_2133N	20
+/* DDR3 ATF default */
+#define DDR3_DEFAULT	21
+
+#endif