linux-cubox-i: Use imx_v7_cbi_hb_defconfig directly

The defconfig file was in essence a trimmed down copy of that config

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
linux-cubox-i: Update to d7a2e737b3

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>