Revert "arm64: defconfig: msm: enable MODULE_SIG for msm chipsets"

This reverts commit 931a5101 ("arm64: defconfig: msm: enable
MODULE_SIG for msm chipsets").

Compilation of Android/DLKMs failing with below error:

Signing kernel module:  bus_timeout_mod.ko
Can't open perl script "./kernel/msm-4.4/scripts/sign-file": \
                                       No such file or directory
ninja: build stopped: subcommand failed.
make: *** [ninja_wrapper] Error 1

CRs-Fixed: 1035494
Change-Id: Iddc618a2467b8ba72a8466c2678b3195ef8fa1c7
Signed-off-by: Kyle Yan <kyan@codeaurora.org>