clk: gxbb: add the SAR ADC clocks and expose them

The HHI_SAR_CLK_CNTL contains three SAR ADC specific clocks:
- a mux clock to choose between different ADC reference clocks (this is
  2-bit wide, but the datasheet only lists the parents for the first
  bit)
- a divider for the input/reference clock
- a gate which enables the ADC clock

Additionally this exposes the ADC core clock (CLKID_SAR_ADC) and
CLKID_SANA (which seems to enable the analog inputs, but unfortunately
there is no documentation for this - we just mimic what the vendor
driver does).

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

include/dt-bindings/clock/gxbb-clkc.h

@@ -14,6 +14,7 @@
 #define CLKID_MPLL2		15
 #define CLKID_SPI		34
 #define CLKID_I2C		22
+#define CLKID_SAR_ADC		23
 #define CLKID_ETH		36
 #define CLKID_USB0		50
 #define CLKID_USB1		51
@@ -21,10 +22,13 @@
 #define CLKID_HDMI_PCLK		63
 #define CLKID_USB1_DDR_BRIDGE	64
 #define CLKID_USB0_DDR_BRIDGE	65
+#define CLKID_SANA		69
 #define CLKID_GCLK_VENCI_INT0	77
 #define CLKID_AO_I2C		93
 #define CLKID_SD_EMMC_A		94
 #define CLKID_SD_EMMC_B		95
 #define CLKID_SD_EMMC_C		96
+#define CLKID_SAR_ADC_CLK	97
+#define CLKID_SAR_ADC_SEL	98
 
 #endif /* __GXBB_CLKC_H */