cnss_prealloc: Add cnss_prealloc driver

This is a snapshot of the cnss_prealloc driver and
associated files as of msm-4.4 commit:

commit 3c45c2a8a2a07a76e2d129d02561d061211e70c8
("Promotion of kernel.lnx.4.4-161119.")

CRs-Fixed: 1094870
Change-Id: Ic98572cf8b66ec936526facd372d04a25a930d75
Signed-off-by: Yuanyuan Liu <yuanliu@codeaurora.org>