clk: meson-g12a: add cpu clock bindings

Add Amlogic G12A Family CPU clocks bindings, only export CPU_CLK since
it should be the only ID used.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lkml.kernel.org/r/20190304131129.7762-2-narmstrong@baylibre.com

include/dt-bindings/clock/g12a-clkc.h

@@ -131,5 +131,6 @@
 #define CLKID_MALI_1				174
 #define CLKID_MALI				175
 #define CLKID_MPLL_5OM				177
+#define CLKID_CPU_CLK				187
 
 #endif /* __G12A_CLKC_H */