sandbox: dts: add sandbox_pmic.dtsi and include it to sandbox.dts and test.dts

This commit adds dtsi file for Sandbox PMIC.
It fully describes the PMIC by:
- i2c emul node - with a default settings of 16 registers
- 2x buck regulator nodes
- 2x ldo regulator nodes

The default register settings are set with preprocessor macros:
- VAL2REG(min[uV/uA], step[uV/uA], val[uV/uA])
- VAL2OMREG(mode id)
Both defined in file:
- include/dt-bindings/pmic/sandbox_pmic.h

The Voltage ranges of each regulator can be found in:
- include/power/sandbox_pmic.h

The new file is included into:
- sandbox.dts
- test.dts

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested on sandbox:
Tested-by: Simon Glass <sjg@chromium.org>
diff --git a/include/dt-bindings/pmic/sandbox_pmic.h b/include/dt-bindings/pmic/sandbox_pmic.h
new file mode 100644
index 0000000..c3d839b
--- /dev/null
+++ b/include/dt-bindings/pmic/sandbox_pmic.h
@@ -0,0 +1,35 @@
+/*
+ *  Copyright (C) 2015 Samsung Electronics
+ *  Przemyslaw Marczak  <p.marczak@samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _DT_BINDINGS_SANDBOX_PMIC_H_
+#define _DT_BINDINGS_SANDBOX_PMIC_H_
+
+/*
+ * Sandbox PMIC - prepare reset values
+ * To provide the default (reset) values as in the real hardware,
+ * the registers are set in i2c pmic emul driver's probe() method.
+ * The default values are defined as below.
+ */
+
+/* Buck operation mode IDs */
+#define BUCK_OM_OFF	0
+#define BUCK_OM_ON	1
+#define BUCK_OM_PWM	2
+#define BUCK_OM_COUNT	3
+
+/* Ldo operation mode IDs */
+#define LDO_OM_OFF	0
+#define LDO_OM_ON	1
+#define LDO_OM_SLEEP	2
+#define LDO_OM_STANDBY	3
+#define LDO_OM_COUNT	4
+
+/* [Value uV/uA]/[Mode ID] to register */
+#define VAL2REG(min, step, val)		(((val) - (min)) / (step))
+#define VAL2OMREG(x)			(x)
+
+#endif