dm: fix build errors generated by last merges

Something was wrong in the merge process into the mainline.
Some added patches access driver structure fields and functions that
have been modified by previous patches.
The patch renames:
 - dev_get_platdata to dev_get_plat
 - dev_get_uclass_platdata to dev_get_uclass_plat
 - ofdata_to_platdata to of_to_plat
 - plat_data_alloc_size to plat_auto
 - priv_auto_alloc_size to priv_auto
 - video_uc_platdata to video_uc_plat

Signed-off-by: Dario Binacchi <dariobin@libero.it>