AST2400: Set kernel preferred provider version

In preparation for supporting AST2500 with a different branch.

Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-ast2400/conf/machine/include/ast2400.inc b/meta-ast2400/conf/machine/include/ast2400.inc
index 58af4bb..97a8834 100644
--- a/meta-ast2400/conf/machine/include/ast2400.inc
+++ b/meta-ast2400/conf/machine/include/ast2400.inc
@@ -3,6 +3,7 @@
 #@DESCRIPTION: Common machine configuration for the Aspeed AST2400 Chip
 
 PREFERRED_PROVIDER_virtual/kernel ?= "linux-obmc"
+PREFERRED_VERSION_linux-obmc ?= "4.4+git%"
 
 UBOOT_MACHINE ?= "versatileab_config"
 UBOOT_ENTRYPOINT ?= "0x40001000"