linux-src.bbclass: Set LINUX_GIT_SRCREV to AUTOREV
linux-src.bbclass: Set LINUX_GIT_SRCREV to AUTOREV

If LINUX_GIT_SRCREV is not set, it should be the HEAD of branch.

Signed-off-by: Trung Do <64081e6b7eb2b24289b8a4e51cef9836ddf28af2@toshiba-tsdv.com>

meta-debian/meta-debian,meta-debian/meta-debian,meta-debian/meta-debian,meta-debian/meta-debian,meta-debian/meta-debian,meta-debian/meta-debian