MLK-16575 gpu: imx: dpu: fetcheco: Correct dpu->fe_priv[] access in dpu_fe_init()

MLK-16575 gpu: imx: dpu: fetcheco: Correct dpu->fe_priv[] access in dpu_fe_init()

The array size of dpu->fe_priv is only 4.  We need to access the correct
entry of the array by comparing the id passed in dpu_fe_init() with
the entries in the fe_ids array instead of using the id directly.
This may avoid out-of-boundary array access on dpu->fe_priv.

Fixes: 936b978c44f3 ("MLK-16075-11 gpu: imx: dpu: Add basic fetcheco units support")
Signed-off-by: Liu Ying <victor.liu@nxp.com>