atmel-isi: use the codec path to support grey format

Signed-off-by: Josh Wu <josh.wu@atmel.com>
media: atmel-isi: increase the burst length for the performance

This could fix the isi overflow issue

Reported-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Josh Wu <josh.wu@atmel.com>
board-dt-sama5: isi: separate the camera power and reset functions

The soc camera provide two functions: .power and .reset.
Current we only use .power() function.

This patch separate power() and reset() functions.

Reported-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Josh Wu <josh.wu@atmel.com>