platform/x86: intel-vbtn: Update tablet mode switch at end of probe

[ Upstream commit 434e5781 ]

ACER Vivobook Flip (TP401NAS) virtual intel switch is implemented as
follow:

   Device (VGBI)
   {
       Name (_HID, EisaId ("INT33D6") ...
       Name (VBDS, Zero)
       Method (_STA, 0, Serialized)  // _STA: Status ...
       Method (VBDL, 0, Serialized)
       {
           PB1E |= 0x20
           VBDS |= 0x40
       }
       Method (VGBS, 0, Serialized)
       {
           Return (VBDS) /* \_SB_.PCI0.SBRG.EC0_.VGBI.VBDS */
       }
       ...
    }

By default VBDS is set to 0. At boot it is set to clamshell (bit 6 set)
only after method VBDL is executed.

Since VBDL is now evaluated in the probe routine later, after the device
is registered, the retrieved value of VBDS was still 0 ("tablet mode")
when setting up the virtual switch.

Make sure to evaluate VGBS after VBDL, to ensure the
convertible boots in clamshell mode, the expected default.

Fixes: 26173179

 ("platform/x86: intel-vbtn: Eval VBDL after registering our notifier")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240329143206.2977734-3-gwendal@chromium.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>