greybus: arche-apb-ctrl: Pass only platform_device to _seq fns

greybus: arche-apb-ctrl: Pass only platform_device to _seq fns

Pass only pointer to platform_device to _seq fns and fetch handle to
arche_apb_ctrl_drvdata from platform_device.

This is preparation for support for dynamic switching between operational
states for the device, where these functions will be called from parent
driver.

Testing Done: Tested on EVT1.2 and DB3.5 platform.

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>