ARM: 8200/1: amba: Add helpers for (un)preparing AMBA clock v12

Add amba_pclk_prepare() and amba_pclk_unprepare() inline functions for
handling the AMBA bus clock by device drivers.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

include/linux/amba/bus.h

@@ -97,6 +97,16 @@ void amba_release_regions(struct amba_device *);
 #define amba_pclk_disable(d)	\
 	do { if (!IS_ERR((d)->pclk)) clk_disable((d)->pclk); } while (0)
 
+static inline int amba_pclk_prepare(struct amba_device *dev)
+{
+	return clk_prepare(dev->pclk);
+}
+
+static inline void amba_pclk_unprepare(struct amba_device *dev)
+{
+	clk_unprepare(dev->pclk);
+}
+
 /* Some drivers don't use the struct amba_device */
 #define AMBA_CONFIG_BITS(a) (((a) >> 24) & 0xff)
 #define AMBA_REV_BITS(a) (((a) >> 20) & 0x0f)