qcacld-3.0: Kbuild: Consistently use ccflags-y

Currently Kbuild uses both cppflags-y and ccflags-y, The kernel Kbuild
documentation recommends using ccflags-y, so consistently use that
everywhere.

Change-Id: Ic5f86bad5d4260f39f98b5ce1b56ba6a69606aa9
CRs-Fixed: 3463792