yocto-bsp/linux-yocto-dev: add genericarm64

For those crazy enough to want to use/test the latest development kernel
for genericarm64, enable it by adding the COMPATIBLE_MACHINE and
KMACHINE.

NOTE: not using the KBRANCH, as neither does the linux-yocto_%.bbappend.
It is taking the default one from the relevant recipe.

(From meta-yocto rev: 85809c64b645ccca4f075e95b86df56d4f858e67)

Signed-off-by: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-yocto-bsp/recipes-kernel/linux/linux-yocto-dev.bbappend

@@ -2,10 +2,12 @@ KBRANCH:genericx86  = "standard/base"
 KBRANCH:genericx86-64  = "standard/base"
 KBRANCH:beaglebone-yocto = "standard/beaglebone"
 
+KMACHINE:genericarm64 ?= "genericarm64"
 KMACHINE:genericx86 ?= "common-pc"
 KMACHINE:genericx86-64 ?= "common-pc-64"
 KMACHINE:beaglebone-yocto ?= "beaglebone"
 
+COMPATIBLE_MACHINE:genericarm64 = "genericarm64"
 COMPATIBLE_MACHINE:genericx86 = "genericx86"
 COMPATIBLE_MACHINE:genericx86-64 = "genericx86-64"
 COMPATIBLE_MACHINE:beaglebone-yocto = "beaglebone-yocto"