usb: phy: twl4030-usb: Silence checkpatch warnings

Silences the following warnings:
WARNING: sizeof *twl should be sizeof(*twl)
WARNING: sizeof *otg should be sizeof(*otg)

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>