conf/machine: Rename machine lsisim to axm5500sim

Signed-off-by: Paul Butler <paul.butler@windriver.com>
axm5500sim: Additional updates for machine name change

- Update machine details for axm5500sim
- Rename defconfig and .inc file path for axm5500sim

Signed-off-by: Paul Butler <paul.butler@windriver.com>
linux-yocto: Replace branch names in custom kernel recipes

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