ARM: AMBA: Add pclk definition for platforms using primecells

Add a dummy clk definition for the APB pclk signal on all platforms
using the AMBA bus infrastructure.  This ensures that these platforms
continue to work when the core amba bus code controls the APB pclk.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-realview/core.c b/arch/arm/mach-realview/core.c
index 595be19..4aba15f 100644
--- a/arch/arm/mach-realview/core.c
+++ b/arch/arm/mach-realview/core.c
@@ -300,8 +300,13 @@
 	.rate	= 24000000,
 };
 
+static struct clk dummy_apb_pclk;
+
 static struct clk_lookup lookups[] = {
-	{	/* UART0 */
+	{	/* Bus clock */
+		.con_id		= "apb_pclk",
+		.clk		= &dummy_apb_pclk,
+	}, {	/* UART0 */
 		.dev_id		= "dev:uart0",
 		.clk		= &ref24_clk,
 	}, {	/* UART1 */