yocto-bsp: Add branch to SRC_URI for custom kernels

Without 'branch' in the SRC_URI, a SRCREV specified for a non-master
KBRANCH will result in a fetch failure since the branch tested by the
fetcher will default to master, which doesn't contain the SRCREV.
This fixes the problem by adding branch=KBRANCH to the SRC_URI.

Fixes [Yocto #6518].

(From meta-yocto rev: 8aeb8715690ea5aa4a36fbe6403d46f53e0f99a5)

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/bsp/substrate/target/arch/common/recipes-kernel/linux/{{ if kernel_choice == \"custom\": }} linux-yocto-custom.bb

@@ -31,9 +31,9 @@ inherit kernel
 require recipes-kernel/linux/linux-yocto.inc
 
 {{ if kernel_choice == "custom" and custom_kernel_remote == "y": }}
-SRC_URI = "{{=custom_kernel_remote_path}};protocol=git;bareclone=1"
+SRC_URI = "{{=custom_kernel_remote_path}};protocol=git;bareclone=1;branch=${KBRANCH}"
 {{ if kernel_choice == "custom" and custom_kernel_remote == "n": }}
-SRC_URI = "git://{{=custom_kernel_local_path}};protocol=file;bareclone=1"
+SRC_URI = "git://{{=custom_kernel_local_path}};protocol=file;bareclone=1;branch=${KBRANCH}"
 
 SRC_URI += "file://defconfig"