The P2SB bus needs to be hidden in some cases so that it does not get
auto-configured by Linux. Add a method for this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Tested-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>

At present we can query the offset of a pinctrl register within the p2sb.
For ACPI we need to get the actual address of the register. Add a function
to handle this and rename the old one to more accurately reflect its
purpose.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>

The Primary-to-Sideband bus (P2SB) is used to access various peripherals
through memory-mapped I/O in a large chunk of PCI space. The space is
segmented into different channels and peripherals are accessed by
device-specific means within those channels. Devices should be added in
the device tree as subnodes of the p2sb.

This adds a uclass and enables it for sandbox.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>