ARM: dts: msm: Remove alias for swr node of external codec

Remove the alias instance for swr node of external codec
as there is only one soundwire master instance in
case of external codec.

Change-Id: Ic7a6713065d9efd2f4d475766f7c6b62f49c7fa2
Signed-off-by: Aditya Bavanari <abavanar@codeaurora.org>