As once the error interrupt is triggered, it can not be cleared.
So, disable it.

No side effect found while testing on sama5d3xek and at91sam9x5ek
boards.
Signed-off-by: NBo Shen <voice.shen@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NMark Brown <broonie@linaro.org>