arm: mach-k3: Add a function for printing DM version

arm: mach-k3: Add a function for printing DM version

Add a function to print version of the DM firmware in use.
The function queries the firmware capabilities first and if
DM split mode bit is set, sends a request to TISCI for
retrieving the version information.

The DM split mode bit indicates that DM is a separate binary
altogether and hence it will have its own versioning.

Signed-off-by: Moteen Shah <m-shah@ti.com>
Reviewed-by: Neha Malcom Francis <n-francis@ti.com>