aiccu: disable on AVR32

In commit 87492d24 ("aiccu: disable
for uClibc 0.9.31/0.9.32"), we made sure it was not possible to select
aiccu with uClibc 0.9.31 and 0.9.32, because they lack dn_skipname().

However, we still have the problem that external AVR32 toolchains can
select aiccu, which causes build failures. Therefore, we also disallow
aiccu on AVR32 altogether. We keep the 0.9.31/0.9.32 exclusions,
because if they are used on other architectures, it would also fail
due to the lack of dn_skipname().

Fixes:

  http://autobuild.buildroot.org/results/a24/a2490d434152625d9208615d83f4c5d6daea79d0/



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