[WCNCR00146539] misc: add CFG80211_VERSION_CODE for cfg80211 API ver check

[Description]
Add CFG80211_VERSION_CODE for cfg80211 API ver check.
When compiling driver with backport package, the target
kernel version and backport kernel version are different,
CFG80211_VERSION_CODE must be specified as the backport
version

[Usage]
To build driver within backport package, we need specify
"export CFG_CFG80211_VERSION=$(BACKPORTED_KERNEL_VERSION)"
in Makefile.x86. Then, Makefile will define CFG80211_VERSION_CODE
which is aligned to backport kernel version automatically.
Default "CFG_CFG80211_VERSION" is undefined.

Change-Id: I8087dc371b68a8cf12fe3c445dc75a5e1cde1891
Feature: misc
Signed-off-by: Awk Jiang <awk.jiang@mediatek.com>
CR-Id: WCNCR00146539
19 files changed