kernel: allow TARGET_KERNEL_MODULES to overwrite kernel modules
kernel: allow TARGET_KERNEL_MODULES to overwrite kernel modules

This is necessary to use compat-wireless since it needs to build a newer
version of cfg80211 (and sometimes mac80211) than the kernel sources version.
There are probably other instances of this type of need.

Change-Id: Ib5bf818286bc20987d8b9f9480a43f3e7690e239

hagar006/platform_manifest,pranav01/platform_manifest,see4ri/lolili,ND-3500/platform_manifest,RR-msm7x30/platform_manifest,knone1/platform_manifest,fallouttester/platform_manifest,Hybrid-Power/startsync