linux-yocto: Remove -custom Kernel

Remove the custom Kernel (standard and preemp-rt) receipes and defconfig
For 3.4 version:
  - change the branch name from "standard/preempt-rt/axxia/base" to
    "standard/preempt-rt/lsi/base"
  - specify the linux kernel type (standard or preempt-rt)
  - set SRC_URI variable to use LSI Github kernel repos instead of local
    git repos.
  - Froce to build from the top of the repo by setting SRCREV to AUTOREV
  - Update LINUX_VERSION variable to 3.4.69 (top)

For 3.10 version:
  - Update LINUX_VERSION variable to 3.10.19 (top)

For core-large-boot packagegroup set busybox as default login_manager
instead of tinylogin. Also, remove tinylogin from the packages list for
core-image-large image and add busybox.

Signed-off-by: Paul Butler <paul.butler@windriver.com>