Input: synaptics-rmi4 - fix SPI device ID

Currently, the ID being set to "rmi4_spi" causes this warning:
"SPI driver rmi4_spi has no spi_device_id for syna,rmi4-spi"

Change the ID to rmi4-spi to stop this warning.

Signed-off-by: Rayyan Ansari <rayyan@ansari.sh>
Link: https://lore.kernel.org/r/20221219133717.1638496-1-rayyan@ansari.sh
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>