serial: lantiq: Get serial id from dts

Get serial id from dts, also keep backward compatible when dts is not
updated.

Signed-off-by: Songjun Wu <songjun.wu@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Songjun Wu 2018-10-16 17:19:04 +08:00 • committed by Greg Kroah-Hartman
commit b871424f57