[PATCH] ARM: OMAP: fix linking

Patch fixes following error, which gets generated if you don't select
IrDA driver for H4.

arch/arm/mach-omap2/built-in.o(.text+0x1844): In function read_gpio_expa'
arch/arm/mach-omap2/built-in.o(.text+0x186c): In function write_gpio_expa'
arch/arm/mach-omap2/built-in.o(.text+0x18ac): In function read_gpio_expa'
arch/arm/mach-omap2/built-in.o(.text+0x18e4): In function write_gpio_expa'
make: *** [.tmp_vmlinux1] Error 1

Signed-off-by: Komal Shah <komal_shah802003@yahoo.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>