Implement kexec-hardboot
"Allows hard booting (i.e., with a full hardware reboot) to a kernel previously loaded in memory by kexec.  This works around the problem of soft-booted kernel hangs due
to improper device shutdown and/or reinitialization."
More info in /arch/arm/Kconfig.

Original author: Mike Kasick <mike@kasick.org>

Ported from Tasssadar/android_kernel_google_msm@6479ff4 by Tasssadar
Thanks @KINGbabasula KINGbabasula/KING_Kernel_One

Change-Id: Ic4b6445a16cd1b3194f614f1fbd85b8a52d896a9