board: phytec: Fix function definitions in AM6x SOM detection

Functions are declared as phytec_am6* and not phytec_am62*.
Update the definitions to match the declarations.

Fixes: 9d152c23279c ("board: phytec: Add SOM detection for AM6x")

Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
Tested-by: John Ma <jma@phytec.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
1 file changed