omap1: htc_herald: Fix compilation warning

Patch fix following compilation warning:
arch/arm/mach-omap1/board-htcherald.c:442:
warning: large integer implicitly truncated to unsigned type

Hopefully this is just a typo.

Signed-off-by: Marek Belisko <marek.belisko@open-nandra.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>