rrdtool: Inherit pkgconfig
rrdtool: Inherit pkgconfig

Fixes
configure: error: Please fix the library issues listed above and try again.

Signed-off-by: Khem Raj <729d64b6f67515e258459a5f6d20ec88b2caf8df@gmail.com>

schnitzeltony/meta-openembedded,openembedded/meta-openembedded,rehsack/meta-openembedded,rehsack/meta-openembedded,schnitzeltony/meta-openembedded,moto-timo/meta-openembedded,openembedded/meta-openembedded,openembedded/meta-openembedded,openembedded/meta-openembedded,rehsack/meta-openembedded,rehsack/meta-openembedded,schnitzeltony/meta-openembedded,rehsack/meta-openembedded,openembedded/meta-openembedded,rehsack/meta-openembedded,openembedded/meta-openembedded,openembedded/meta-openembedded,moto-timo/meta-openembedded,rehsack/meta-openembedded,schnitzeltony/meta-openembedded,moto-timo/meta-openembedded,schnitzeltony/meta-openembedded,openembedded/meta-openembedded,schnitzeltony/meta-openembedded,moto-timo/meta-openembedded,schnitzeltony/meta-openembedded,moto-timo/meta-openembedded