poky.conf: remove unnecessary INHERIT += "create-spdx"

Already inherited through meta/conf/distro/defaultsetup.conf

(From meta-yocto rev: db24e48498b2d40131b871f6eafeb7a67da343f0)

Signed-off-by: Michael Opdenacker <michael.opdenacker@rootcommit.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-poky/conf/distro/poky.conf

@@ -73,6 +73,3 @@ INIT_MANAGER ?= "${POKY_INIT_MANAGER}"
 
 # We need debug symbols so that SPDX license manifests for the kernel work
 KERNEL_EXTRA_FEATURES:append = " features/debug/debug-kernel.scc"
-
-# Enable creation of SPDX manifests by default
-INHERIT += "create-spdx"