ARM: mx5: dynamically allocate imx-keypad devices

Add support for dynamical allocation of imx-keypad on mx5 platform.

After moving to dynamically registration of the keypad, the keypad clock
name needs to change accordingly.

The reason is that the original mx5 keypad platform_device id was 0,
now we use id=-1 as per arch/arm/plat-mxc/devices/platform-imx-keypad.c.

Tested keypad successfully on a MX51_3DS board.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mx5/Kconfig b/arch/arm/mach-mx5/Kconfig
index 777740b..f2f0731 100644
--- a/arch/arm/mach-mx5/Kconfig
+++ b/arch/arm/mach-mx5/Kconfig
@@ -50,6 +50,7 @@
 config MACH_MX51_3DS
 	bool "Support MX51PDK (3DS)"
 	select SOC_IMX51
+	select IMX_HAVE_PLATFORM_IMX_KEYPAD
 	select IMX_HAVE_PLATFORM_IMX_UART
 	select IMX_HAVE_PLATFORM_SDHCI_ESDHC_IMX
 	select IMX_HAVE_PLATFORM_SPI_IMX
@@ -77,6 +78,7 @@
 config MACH_EUKREA_MBIMX51_BASEBOARD
 	prompt "Eukrea MBIMX51 development board"
 	bool
+	select IMX_HAVE_PLATFORM_IMX_KEYPAD
 	select IMX_HAVE_PLATFORM_SDHCI_ESDHC_IMX
 	help
 	  This adds board specific devices that can be found on Eukrea's