uclibc: make sure the default configuration doesn't ask questions

Since new configuration options have been added in 0.9.31, the value
of these configuration options should be determined, either by the
default configuration file we provide, or by uclibc.mk process.

The locale generation process should probably be improved in order to
allow building other locales than just en_US.

[Peter: fixup locale handling, add PROGRAM__NAME to defconfig]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>