The devel package of nss doesn't include the static libraries libnssb.a and libnssckfw.a These libraries are needed when building PKCS#11 modules. Since these are fairly specialized libraries and not needed by most NSS developers, one option would be to have a separate package, something like nss-pkcs11-devel that would contain these 2 libraries.
The package you suggested is already available, please install package nss-pkcs11-devel.