msm8974: add support for dtbtool

Change-Id: I577d17301b27f7cf2fe85ad18f848110758b56a8
dtbtool: fuck this

* we're shipping a blob for now
* also - use cm's dtbtool, we don't need our own

Change-Id: I0a938960b7103a48639522049a4bfa07743390d2
msm8974: build libnetcmdiface

Change-Id: I9e69bdd789894e00561e997c2d9e7583ca6286f4