video: omap2: Rename amplifier-opa362 to encoder-opa362

Signed-off-by: Marek Belisko <marek@goldelico.com>
video: omap2: encoder-opa362: Convert to new gpio API + drop non-dt probe

Signed-off-by: Marek Belisko <marek@goldelico.com>
arm: dts: omap3-gta04: Update enable gpio node

When using new api gpios must have prefix enable
(hardcoded in encoder-opa362 code).