libc/uClibc: fix verbosity level for uClibc >= 0.9.30

uClibc >= 0.9.30 supports three verbosity levels, according to "make help":

V="" - Quiet build (default)
V=1 - Brief build (show defines, ld flags)
V=2 - Very verbose build

I think older versions of uClibc treat V=2 the same as V=1.
For current uClibc, only V=2 shows the full command lines.

Signed-off-by: Johannes Stezenbach <js@sig21.net>

 # Default test suite configuration

 # Default DejaGnu configuration

 DG_TOOLNAME = gcc

 DG_TARGET_HOSTNAME = 127.0.0.1

 DG_TARGET_USERNAME = root

 # Default tests

 DG_C_TESTS = 

 DG_CPP_TESTS =