nitrogen6x_defconfig: Enable SELINUX in configuartion (see 8ad5bc5)

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
nitrogen6x_defconfig: ENGR00290619 ethernet:Tune ethernet performance

According to AOSP's recommended kernel config, RT scheduler is only needed.
Strictly align with AOSP, it will contribute about 40M in Gigabit net
performance.

See commit 8e2265b

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
nitrogen6x_defconfig: ENGR00284562 Net:adjust net config

Android vpn API setFwmarkRule needs enable CONFIG_IP_MULTIPLE_TABLES.
Or it will throw the following exception:
I/LegacyVpnRunner( 2685): Aborting
I/LegacyVpnRunner( 2685): java.lang.IllegalStateException: command '32
                        interface fwmark rule add ppp0' failed with '400
                        32 Failed to add fwmark rule (Success)'
I/LegacyVpnRunner( 2685):at com.android.server.NetworkManagementService.
                        setMarkedForwarding(NetworkManagementService.java:1475)
I/LegacyVpnRunner( 2685):at com.android.server.ConnectivityService$VpnCallback
                        .setMarkedForwarding(ConnectivityService.java:3779)
I/LegacyVpnRunner( 2685):at com.android.server.connectivity.Vpn$LegacyVpnRunne
                        .execute(Vpn.java:1101)
Additionally, I clean up net config to strictly align with AOSP's new
recommended kernel config in http://source.android.com/devices/tech/kernel.html

See commit ee716a3.

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
nitrogen6x_defconfig: enable PL310_ERRATA_769419 (see commit e693aca)

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
nitrogen6x_defconfig: enable SHA256 (see commit 2aae904)

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
nitrogen6x_defconfig: enable EXT4 security (see commit 08a5bdf)

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
nitrogen6x_defconfig: disable MMC_BLOCK_DEFERRED_RESUME (see commit 92bf1e0)

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
nitrogen6x_defconfig: enable GPU_LOW_MEMORY_KILLER (see commit 2f375da)

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
nitrogen6x_defconfig: disable ANDROID_RESERVED_MEMORY_ACCOUNT (see commit d905127)

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>