sunxi: power: Compile sy8106a driver only during SPL build

Driver for that regulator is used only in SPL and it uses old I2C
interface. If we want to use DM I2C in U-Boot proper, compilation of
this driver has to be limited only to SPL.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Reviewed-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drivers/power/sy8106a.c

@@ -12,6 +12,7 @@
 #define SY8106A_VOUT1_SEL 1
 #define SY8106A_VOUT1_SEL_ENABLE (1 << 7)
 
+#ifdef CONFIG_SPL_BUILD
 static u8 sy8106a_mvolt_to_cfg(int mvolt, int min, int max, int div)
 {
 	if (mvolt < min)
@@ -27,3 +28,4 @@ int sy8106a_set_vout1(unsigned int mvolt)
 	u8 data = sy8106a_mvolt_to_cfg(mvolt, 680, 1950, 10) | SY8106A_VOUT1_SEL_ENABLE;
 	return i2c_write(SY8106A_I2C_ADDR, SY8106A_VOUT1_SEL, 1, &data, 1);
 }
+#endif