rockchip: spl: Support full-speed CPU in SPL

Add a feature which speeds up the CPU to full speed in SPL to minimise
boot time. This is only supported for certain boards (at present only
jerry).

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-rockchip/rk3288/Kconfig b/arch/arm/mach-rockchip/rk3288/Kconfig
index d0a7276..ed89c3e 100644
--- a/arch/arm/mach-rockchip/rk3288/Kconfig
+++ b/arch/arm/mach-rockchip/rk3288/Kconfig
@@ -16,6 +16,15 @@
 	  WiFi. It includes a Chrome OS EC (Cortex-M3) to provide access to
 	  the keyboard and battery functions.
 
+config ROCKCHIP_FAST_SPL
+	bool "Change the CPU to full speed in SPL"
+	depends on TARGET_CHROMEBOOK_JERRY
+	help
+	  Some boards want to boot as fast as possible. We can increase the
+	  CPU frequency in SPL if the power supply is configured to the correct
+	  voltage. This option is only available on boards which support it
+	  and have the required PMIC code.
+
 config SYS_SOC
 	default "rockchip"