toolchain: more verbose in crosstool-ng backend

By default, Crosstool-NG hides all the details of the toolchain build
process. However, this is inconsistent with the typical Buildroot
build, and the rotating progress thing makes log file resulting from
redirecting the Buildroot output a bit unusable. Therefore, switch the
Crosstool-NG configuration to a more verbose default.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>