arm: imx: hab: Prefix authenticate_image with imx_hab

arm: imx: hab: Prefix authenticate_image with imx_hab

Tidy up the HAB namespace a bit by prefixing external functions with
imx_hab. All external facing functions past this point will be prefixed in
the same way to make the fact we are doing IMX HAB activities clear from
reading the code. authenticate_image() could mean anything
imx_hab_authenticate_image() is on the other hand very explicit.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Sven Ebenfeld <sven.ebenfeld@gmail.com>
Cc: George McCollister <george.mccollister@gmail.com>
Cc: Breno Matheus Lima <brenomatheus@gmail.com>
Tested-by: Breno Lima <breno.lima@nxp.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>