package/tpm2-tools: disable on uClibc, due to c16rtomb()

package/tpm2-tools: disable on uClibc, due to c16rtomb()

Since upstream commit eca77c1419617a8e2d6d8008bac716878b0c27ca, the
c16rtomb() wide-char function is used by tpm2-tools, but this function
is not implemented by uClibc.

This commit first appeared in tpm-tools 4.2, and therefore the bump
from version 4.1.2 to 4.3.2 in commit
91aa6efa8588bf7617cc4a640eb55052b524ceb7 causes a build failure on
uClibc configurations.

An issue was reported at
https://github.55860.com/tpm2-software/tpm2-tools/issues/2785, but in
the mean time, we disable tpm2-tools on uClibc configurations.

Fixes:

  http://autobuild.buildroot.net/results/f91950b1e5620844bb04a65252d0836da736965d/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>