imx: imx_csu: Add a simple CSU layer

- Add a header to define imx_csu_init().
- Defines the Central Security Unit's Config Security Level
  permission bits.
- Define CSU_CSL_OPEN_ACCESS permission bitmask
- Run a loop to setup peripheral CSU permissions

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
2 files changed