mpir: fix build on powerpc64le

The optimized powerpc64 code is not compatible with powerpc64le, so use
the generic MPIR code on powerpc64le.

Fixes:

   http://autobuild.buildroot.net/results/17e523be894b60d7a9b2a3303f02c3fb34816828/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
1 file changed