mfd: rn5t618: Add Ricoh RN5T567 PMIC support

The Ricoh RN5T567 is from the same family as the Ricoh RN5T618 is,
the differences are:

+ DCDC4
+ Slightly different output voltage/currents
+ 32kHz Output
- ADC/Charger capabilities

Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

include/linux/mfd/rn5t618.h

@@ -20,6 +20,7 @@
 #define RN5T618_OTPVER			0x01
 #define RN5T618_IODAC			0x02
 #define RN5T618_VINDAC			0x03
+#define RN5T618_OUT32KEN		0x05
 #define RN5T618_CPUCNT			0x06
 #define RN5T618_PSWR			0x07
 #define RN5T618_PONHIS			0x09
@@ -38,6 +39,7 @@
 #define RN5T618_DC1_SLOT		0x16
 #define RN5T618_DC2_SLOT		0x17
 #define RN5T618_DC3_SLOT		0x18
+#define RN5T618_DC4_SLOT		0x19
 #define RN5T618_LDO1_SLOT		0x1b
 #define RN5T618_LDO2_SLOT		0x1c
 #define RN5T618_LDO3_SLOT		0x1d
@@ -54,12 +56,16 @@
 #define RN5T618_DC2CTL2			0x2f
 #define RN5T618_DC3CTL			0x30
 #define RN5T618_DC3CTL2			0x31
+#define RN5T618_DC4CTL			0x32
+#define RN5T618_DC4CTL2			0x33
 #define RN5T618_DC1DAC			0x36
 #define RN5T618_DC2DAC			0x37
 #define RN5T618_DC3DAC			0x38
+#define RN5T618_DC4DAC			0x39
 #define RN5T618_DC1DAC_SLP		0x3b
 #define RN5T618_DC2DAC_SLP		0x3c
 #define RN5T618_DC3DAC_SLP		0x3d
+#define RN5T618_DC4DAC_SLP		0x3e
 #define RN5T618_DCIREN			0x40
 #define RN5T618_DCIRQ			0x41
 #define RN5T618_DCIRMON			0x42
@@ -221,8 +227,14 @@ enum {
 	RN5T618_REG_NUM,
 };
 
+enum {
+	RN5T567 = 0,
+	RN5T618,
+};
+
 struct rn5t618 {
 	struct regmap *regmap;
+	long variant;
 };
 
 #endif /* __LINUX_MFD_RN5T618_H */