As I mentioned That I Cloned warrior branch of poky, meta-raspberrypi and meta-openembedded.
nghttp2 recipe is already in my repository under "meta-openembedded/meta-networking/recipes-support/nghttp2"
but the problem is still persistent.
I tried to add nghttp2 as RDENPENDS in curl and it compiled successfully but libnghttp2 was not part of my image.
If I add nghttp2 in conf/local.conf inside "IMAGE_INSTALL_append ", the libnghttp2 becomes the part of my image under /usr/lib but again curl doesn't support http2.