linux-yocto: introduce 4.15 bbappend for genericx86* BSPs

Sync with stable kernel release 4.15.3 in oe-core.

(From meta-yocto rev: b86dc8e9954b30202ac09ece96a2a3dc55f429b9)

Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-yocto-bsp/recipes-kernel/linux/linux-yocto_4.15.bbappend

@@ -0,0 +1,14 @@
+KBRANCH_genericx86  = "v4.15/standard/base"
+KBRANCH_genericx86-64  = "v4.15/standard/base"
+
+KMACHINE_genericx86 ?= "common-pc"
+KMACHINE_genericx86-64 ?= "common-pc-64"
+
+SRCREV_machine_genericx86    ?= "a6a3a6a73d628798fc6eb6832bf829a9ea43f6bd"
+SRCREV_machine_genericx86-64 ?= "a6a3a6a73d628798fc6eb6832bf829a9ea43f6bd"
+
+COMPATIBLE_MACHINE_genericx86 = "genericx86"
+COMPATIBLE_MACHINE_genericx86-64 = "genericx86-64"
+
+LINUX_VERSION_genericx86 = "4.15.3"
+LINUX_VERSION_genericx86-64 = "4.15.3"