irqchip/imx-intmux: Use dev_err_probe() to simplify error handling

dev_err_probe() can reduce code size, uniform error handling and record the
defer probe reason etc., use it to simplify the code.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1597126576-18383-1-git-send-email-Anson.Huang@nxp.com