net: cnss: enable rome_vreg regulator for cnss SDIO

rome_vreg regulator is a fixed regulator and this regulator
control by PMIC gpio which is used as vdd supply for
the wlan module SDIO based interface. Enable rome_vreg
voltage regulators to enable the power up support in CNSS SDIO
platform driver.

Change-Id: I629bacf89029ade87d880972a972098447fc79e2
Signed-off-by: Sarada Prasanna Garnayak <sgarna@codeaurora.org>