bus: mhi: host: pci_generic: Add Telit FN990B40 modem support

Add SDX72 based modem Telit FN990B40, reusing FN920C04 configuration.

01:00.0 Unassigned class [ff00]: Qualcomm Device 0309
        Subsystem: Device 1c5d:201a

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
[mani: added sdx72 in the comment to identify the chipset]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20250716091836.999364-1-dnlplm@gmail.com