ARM: imx: Get rid of only i.MX8M SMCCC arch call

This is the only place where i.MX8M code does SMCCC call, remove it.
The output has little value as it prints some part of commit ID, and
worse, if there is no SMC handler installed, the code outright hangs
or crashes the system.

By removing this one instance of SMCCC call, U-Boot no longer depends
on SMC handlers and can boot without hanging in any case. If there is
a need to dump this commit ID, use CMD_SMC instead and do 'smc' call
from U-Boot shell or scripts instead of hard-coding SMCCC dependency
into architecture code. This particular code can be replaced by:
 => smc 0xc2000003 0 0 0 0 0 0

Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>