mfd: pm8008: Fix module autoloading

Add the missing module device table alias to that the driver can be
autoloaded when built as a module.

Cc: stable@vger.kernel.org      # 5.14
Fixes: 6b149f33 ("mfd: pm8008: Add driver for QCOM PM8008 PMIC")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230526091646.17318-2-johan+linaro@kernel.org