only use chacha_vec.c when arm_float_abi==hard

Change-Id: Id0eb1d6f7f25944ca2ad37d735ba4f07bcfcc191
Reviewed-by: Andras Becsi <andras.becsi@digia.com>
Include atomicops_internals_x86_gcc.cc when compiling for ia32

This is needed for the embedded emulators and should be squashed
with the corresponding patch on the next update.

Change-Id: I9ece131df6ba23045dad741278651399a67639e7
Reviewed-by: Zeno Albisser <zeno.albisser@digia.com>