I Don't understand the purpose of redefining the BR2_USE_WCHAR with Negation after the comment.
config BR2_PACKAGE_RRDTOOL
bool "rrdtool"
depends on **BR2_USE_WCHAR**
select BR2_PACKAGE_FREETYPE
select BR2_PACKAGE_LIBART
select BR2_PACKAGE_LIBPNG
select BR2_PACKAGE_ZLIB
help
RRDtool is the OpenSource industry standard, high performance
data logging and graphing system for time series data.
http://oss.oetiker.ch/rrdtool/
comment "rrdtool needs a toolchain w/ wchar"
depends on **!BR2_USE_WCHAR**