site avr32 common: add pthread size

[vuplus_openembedded] / site / endian-big

ac_cv_c_littleendian=${ac_cv_c_littleendian=no}
ac_cv_c_bigendian=${ac_cv_c_bigendian=yes}

# libnet
ac_cv_libnet_endianess=${ac_cv_libnet_endianess=big}