ASoC: stm32: sai: set sai as mclk clock provider

Add master clock generation support in STM32 SAI.
The master clock provided by SAI can be used to feed a codec.
Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/stm/stm32_sai.h

@@ -91,6 +91,9 @@
 #define SAI_XCR1_OSR_SHIFT	26
 #define SAI_XCR1_OSR		BIT(SAI_XCR1_OSR_SHIFT)
 
+#define SAI_XCR1_MCKEN_SHIFT	27
+#define SAI_XCR1_MCKEN		BIT(SAI_XCR1_MCKEN_SHIFT)
+
 /******************* Bit definition for SAI_XCR2 register *******************/
 #define SAI_XCR2_FTH_SHIFT	0
 #define SAI_XCR2_FTH_MASK	GENMASK(2, SAI_XCR2_FTH_SHIFT)