defconfig: mdm: Remove some of the configs for mdm targets

Remove some of the governors which are not required and
disable highmem config also.Enable stack protector.

Change-Id: I279dc93cd8aabbc4c700aa7783275acccd3c3693
Signed-off-by: Venkatesh Yadav Abbarapu <vabbar@codeaurora.org>