serial: lantiq: Remove unnecessary print function dev_err()

Function dev_err() is redundant because platform_get_irq()
already prints an error.

Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Acked-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
Link: https://lore.kernel.org/r/20250401080337.2187400-1-nichen@iscas.ac.cn


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>