kexec/ppc64: disabling exception handling when building the purgatory
    
    Backport the following commit from upstream kexec-tools:
    
    commit 335bad7
    Author: Laurent Dufour <ldufour@linux.vnet.ibm.com>
    Date:   Tue Jul 22 18:22:28 2014 +0200
    
        kexec/ppc64: disabling exception handling when building the purgatory
    
        Some Linux distributions would like to turn on the GCC exception handling
        by default. As this option introduces symbols in the built code that are
        defined in a separate shared library, this is not a good idea to have such
        an option activated when building the purgatory.
    
        This patch forces the exception handling to be turned off when building the
        purgatory on ppc64 BE and LE.
    
        Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
        Signed-off-by: Simon Horman <horms@verge.net.au>
    
    This is part of the work to enable ppc64le.
    
    Signed-off-by: WANG Chao <chaowang@redhat.com>
    Acked-by: Vivek Goyal <vgoyal@redhat.com>