defconfig: sdm429w: Remove support of ICNSS driver

ICNSS platform driver is applicable to iHelium based
chipsets. Remove ICNSS driver config from sdm429w defconfig.

Change-Id: I67f512e906a7c5d626c44e96d44e30d04e8b7ada
Signed-off-by: Govind Singh <govinds@codeaurora.org>