lava_rpc_connector: Switch USE_TUXSUITE_FVP to assumed default of enabled

I.e. if a job doesn't have explicit the param with "0" value, assume it's
enabled.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: I3c271d2a7de5b31ef94b018dd95ebfa9d96ddc6b
1 file changed