omap2/3/4: ehci: avoid compiler error with touchbook

the early_param() call in board-omap3touchbook.c expands to:

static const char __setup_str_early_touchbook_revision[]
	__section(.init.rodata) _aligned(1) = tbr;
[...]

and we have a non-const variable being added to the
same section:

static struct ehci_hcd_omap_platform_data ehci_pdata
__section(.init.rodata);

because of that, gcc generates a section type conflict
which can (and actually should) be avoided by marking
const every variable marked with __initconst.

This patch fixes that for the ehci_hdc_omap_platform_data.

Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/usb-ehci.c b/arch/arm/mach-omap2/usb-ehci.c
index f1df873..ee9f548 100644
--- a/arch/arm/mach-omap2/usb-ehci.c
+++ b/arch/arm/mach-omap2/usb-ehci.c
@@ -70,7 +70,7 @@
 /*
  * setup_ehci_io_mux - initialize IO pad mux for USBHOST
  */
-static void setup_ehci_io_mux(enum ehci_hcd_omap_mode *port_mode)
+static void setup_ehci_io_mux(const enum ehci_hcd_omap_mode *port_mode)
 {
 	switch (port_mode[0]) {
 	case EHCI_HCD_OMAP_MODE_PHY:
@@ -213,7 +213,7 @@
 	return;
 }
 
-void __init usb_ehci_init(struct ehci_hcd_omap_platform_data *pdata)
+void __init usb_ehci_init(const struct ehci_hcd_omap_platform_data *pdata)
 {
 	platform_device_add_data(&ehci_device, pdata, sizeof(*pdata));
 
@@ -229,7 +229,7 @@
 
 #else
 
-void __init usb_ehci_init(struct ehci_hcd_omap_platform_data *pdata)
+void __init usb_ehci_init(const struct ehci_hcd_omap_platform_data *pdata)
 
 {
 }