gpu: ion: ion_carveout_heap: fix for 3.4

__arch_ioremap is no longer available, use __arm_ioremap instead.

Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>