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>

package/mpir/mpir.mk

@@ -31,4 +31,9 @@ ifeq ($(BR2_mips_32r6)$(BR2_mips_64r6),y)
 MPIR_CONF_ENV += MPN_PATH="generic"
 endif
 
+# Optimized powerpc64 code is not suitable for powerpc64le
+ifeq ($(BR2_powerpc64le),y)
+MPIR_CONF_ENV += MPN_PATH="generic"
+endif
+
 $(eval $(autotools-package))