Enable ARM_PIE to fix boot

Fixes :
init: critical process 'servicemanager' exited 4 times in 4 minutes; rebooting into recovery mode

Change-Id: Idf6dc255aeb0b6a85ea89f548bf65f4e700ab649
TARGET_CPU_VARIANT := arm11

Implement armv6 optimized strlen from glibc 2.18
https://github.com/androidarmv6/android_bionic/commit/12b16f859dc0bbf45344b74512e22c49266cba00

Change-Id: I9145c51d125c9ef70521d003788669e258fa8d2f