defconfig: msm: Enable CC_STACKPROTECTOR_REGULAR for msm8937

Enable CC_STACKPROTECTOR_REGULAR instead of CC_STACKPROTECTOR_STRONG
as arm-eabi-4.8 does not support CC_STACKPROTECTOR_STRONG.
msm8937_defconfig file is used for msm8937 and msmgold SoCs and
msmcortex_defconfig file is used for msmtitainum SoC.

Change-Id: I654a4d88ce9bcce2d103fd6da55d461317ccaac3
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>