regulator: tps65217: Remove *rdev[] from struct tps65217

Now this driver uses devm_regulator_register() so we don't need to save rdev
pointer to tps->rdev[i] for cleanup.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>