memory: tegra30-emc: Simplify and handle deferred probe with dev_err_probe()

memory: tegra30-emc: Simplify and handle deferred probe with dev_err_probe()

Certain calls, like clk_get, can cause probe deferral and driver should
handle it.  Use dev_err_probe() to fix that and also change other
non-deferred errors cases to make the code simpler.

Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>