clocksource: imx/imx51: ipipe: add support for user-visible TSC

Expose the clocksource to userland processes via the ARM-specific
user-TSC interface.

arch/arm/mach-imx/mach-imx51.c

@@ -88,6 +88,11 @@ static void __init imx51_dt_init(void)
 static void __init imx51_init_late(void)
 {
 	mx51_neon_fixup();
+#ifdef CONFIG_IPIPE
+	/* Allow user-space access to emulated tsc */
+	imx_set_aips(IMX_IO_ADDRESS(0x73f00000));
+	imx_set_aips(IMX_IO_ADDRESS(0x83f00000));
+#endif
 	imx51_pm_init();
 }