firmware: ti_sci: Bind sysreset driver when enabled

The sysreset TI-SCI API is available with TI-SCI always, there is no need
for a DT node to describe the availability of this. If the sysreset driver
is available then bind it during ti-sci probe.

Remove the unneeded device tree matching.

Signed-off-by: Andrew Davis <afd@ti.com>
Tested-by: Jonathan Humphreys <j-humphreys@ti.com>
Reviewed-by: Neha Malcom Francis <n-francis@ti.com>