beaglebone.conf: Switch to generating ext4 rootfs images

Signed-off-by: Joel <joel@joelboxx.am.dhcp.ti.com>
Update README with packages added

Signed-off-by: Joel <joel@joelboxx.am.dhcp.ti.com>
beaglebone-image: Add some more kernel tools

Signed-off-by: Joel <joel@joelboxx.am.dhcp.ti.com>
serial-getty service: Add linux as default TERM

In poky with systemd enabled, vt102 is selected for getty
causing user to experience a very crappy terminal. Default
TERM to linux.

Signed-off-by: Joel Fernandes <joelf@ti.com>