build: disable Windows warnings for insecure funtions

build: disable Windows warnings for insecure funtions

Microsoft CRT defines Windows-specific secure alternatives to
standard library functions and triggers warnings when "insecure"
functions are used [1]. However, calling code already has all
necessary checks around those functions, so these warnings are not
useful for DPDK. MinGW provides its own CRT without this issue.

[1]:
https://docs.microsoft.com/en-us/cpp/c-runtime-library/security-features-in-the-crt?view=msvc-160

Disable this by defining -D_CRT_SECURE_NO_WARNINGS.

Signed-off-by: Nick Connolly <nick.connolly@mayadata.io>
Acked-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Acked-by: Pallavi Kadam <pallavi.kadam@intel.com>