devicetree.bbclass: Add virtual provider for dtb

Add virtual provider for dtb. This class can be used to generate dtb
from static devicetree, for reference see meta-xilinx layer
meta-xilinx/meta-xilinx-bsp/recipes-bsp/device-tree/device-tree.bb

By providing a virtual provider we can use it to differentiate between
in-kernel dtb or an external one. This can be set in local.conf as
PREFERRED_PROVIDER_virtual/dtb = "devicetree"

(From OE-Core rev: a7d52dbffd0da95de82d910c595a6c27d9b2ad0d)

Signed-off-by: Manjukumar Matha <manjukumar.harthikote-matha@xilinx.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/meta/classes/devicetree.bbclass b/meta/classes/devicetree.bbclass
index 8fe5a5ed79..e1f377911d 100644
--- a/meta/classes/devicetree.bbclass
+++ b/meta/classes/devicetree.bbclass
@@ -27,6 +27,8 @@ inherit deploy kernel-arch
 
 COMPATIBLE_MACHINE ?= "^$"
 
+PROVIDES = "virtual/dtb"
+
 PACKAGE_ARCH = "${MACHINE_ARCH}"
 
 SYSROOT_DIRS += "/boot/devicetree"