clk: sunxi-ng: Add feature to find closest rate

The default behaviour of clocks in the sunxi-ng driver is to select a
clock rate that is closest to but less than the requested rate.

Add the CCU_FEATURE_CLOSEST_RATE flag, which can be used to allow clocks
to find the closest rate instead.

Acked-by: Maxime Ripard <[email protected]>
Acked-by: Jernej Skrabec <[email protected]>
Signed-off-by: Frank Oltmanns <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Chen-Yu Tsai <[email protected]>

Author: Frank Oltmanns

drivers/clk/sunxi-ng/ccu_common.h

@@ -18,6 +18,7 @@
 #define CCU_FEATURE_MMC_TIMING_SWITCH	BIT(6)
 #define CCU_FEATURE_SIGMA_DELTA_MOD	BIT(7)
 #define CCU_FEATURE_KEY_FIELD		BIT(8)
+#define CCU_FEATURE_CLOSEST_RATE	BIT(9)
 
 /* MMC timing mode switch bit */
 #define CCU_MMC_NEW_TIMING_MODE		BIT(30)