ata: sata_gemini: Remove unused gemini_sata_reset_bridge()

gemini_sata_reset_bridge() was added in 2017 by the initial
commit be4e456e ("ata: Add driver for Faraday Technology FTIDE010")
but has never been used.

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>