mfd: qcom_rpm: write fw_version to CTRL_REG

[ Upstream commit 504e4175829c44328773b96ad9c538e4783a8d22 ]

This is required as part of the initialization sequence on certain SoCs.

If these registers are not initialized, the hardware can be unresponsive.
This fixes the driver on apq8060 (HP TouchPad device).

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>