mk: use extra cflags when linking with compiler
mk: use extra cflags when linking with compiler

When using the compiler to link applications, include EXTRA_CFLAGS. This
is needed, for example, when cross-compiling, to pass --sysroot.
GCC cross-compilers built with Yocto don't use the --with-sysroot option,
making it necessary to pass --sysroot command-line option.

Signed-off-by: John Jacques <b6a09b6587efac31fa4cf411e52d15f074149490@intel.com>
Signed-off-by: Gage Eads <40e74f4682b7928915cbf15b25c304eff85f59a4@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk