Disable CONFIG_STRICT_MEMORY_RWX

CONFIG_STRICT_MEMORY_RWX has good intentions. But it actually opens the kernel up to more vulnerabilities unless security patches are applied.

https://www.codeaurora.org/projects/security-advisories/configstrictmemoryrwx-not-strictly-enforced-cve-2013-4737

The security patch that fixes CONFIG_STRICT_MEMORY_RWX takes up 1.9 MB of kernel space and about 1 MB of user memory. The only known exploit for what it fixes is ironically only for the unpatched version of this config.

Upstream Linux, which is usually very sensitive to security issues has
not implemented this config. In fact, Ubuntu has explicitly removed it
from their MSM builds http://web.archiveorange.com/archive/v/UsR4n0n1MLugFsH52gbL

Let's save the memory and just turn it off.

Change-Id: I7ddff43bb76fb5ddb0c144d891bdf8ed2c19c9a5