Move NXP JNI and DeviceHost implementation into separate dir.

Preparation for the new NCI stack. The idea is to
build either the NXP or the NCI stack, triggered
by a makefile switch. To that end, move the
DeviceHost and JNI implementations in their own
directory, so we can build them only if needed.

Change-Id: I8579ec30ceb1908e4cd180cfbd10224aa4bddb8d
22 files changed