dt-bindings: clock: meson8b: export the CPU post dividers

There are four CPU clock post dividers:
- ABP
- PERIPH (used as input for the ARM global timer and ARM TWD timer)
- AXI
- L2 DRAM

Export these so we can use them in .dts files.
Signed-off-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: NJerome Brunet <jbrunet@baylibre.com>
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181122214017.25643-2-martin.blumenstingl@googlemail.com

include/dt-bindings/clock/meson8b-clkc.h

@@ -103,5 +103,9 @@
 #define CLKID_MPLL1		94
 #define CLKID_MPLL2		95
 #define CLKID_NAND_CLK		112
+#define CLKID_ABP		124
+#define CLKID_PERIPH		126
+#define CLKID_AXI		128
+#define CLKID_L2_DRAM		130
 
 #endif /* __MESON8B_CLKC_H */