bus: mhi: host: pci_generic: add support for Telit FE990 modem

Add support for Telit FE990 that has the same configuration as FN990:

$ lspci -vv
04:00.0 Unassigned class [ff00]: Qualcomm Device 0308
    Subsystem: Device 1c5d:2015

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://lore.kernel.org/r/20230804094039.365102-1-dnlplm@gmail.com


[mani: minor update to commit subject and adjusted comment]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>