linux-imx

arc: remove unnecessary prom.h includes

Remove unnecessary prom.h includes in preparation to remove prom.h.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Grant Likely <grant.likely@linaro.org>