Bug#875621: linux: ThinkPad X270 Synaptics touchpad: please enable CONFIG_RMI4_SMB

[Felicia Pacifica]

Additional info for the kernel I compiled with Synaptics RMI4 bus 
support -> RMI4 SMB Support enabled:

dmesg |grep -i smbus
[    1.401103] i801_smbus 0000:00:1f.3: SPD Write Disable is set
[    1.401130] i801_smbus 0000:00:1f.3: SMBus using PCI interrupt
[    2.213572] psmouse serio1: synaptics: Trying to set up SMBus access
[    2.216948] rmi4_smbus 0-002c: registering SMbus-connected sensor