regulator: qcom-rpmh: fix pm8009 ldo7

Use the correct name to avoid ldo7 commands being sent to ldo6's address.

Fixes: 06369bcc

 ("regulator: qcom-rpmh: Add support for SM8150")
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20210211034935.5622-1-jonathan@marek.ca
Signed-off-by: Mark Brown <broonie@kernel.org>