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/board-zoom3.c b/arch/arm/mach-omap2/board-zoom3.c
index d3e3cd5..cd3e40c 100644
--- a/arch/arm/mach-omap2/board-zoom3.c
+++ b/arch/arm/mach-omap2/board-zoom3.c
@@ -52,7 +52,7 @@
 #define board_mux	NULL
 #endif
 
-static struct ehci_hcd_omap_platform_data ehci_pdata __initconst = {
+static const struct ehci_hcd_omap_platform_data ehci_pdata __initconst = {
 	.port_mode[0]		= EHCI_HCD_OMAP_MODE_UNKNOWN,
 	.port_mode[1]		= EHCI_HCD_OMAP_MODE_PHY,
 	.port_mode[2]		= EHCI_HCD_OMAP_MODE_UNKNOWN,