UPSTREAM: firmware: arm_ffa: Simplify probe function

When the driver core calls the probe callback it already checked that
the devices match, so there is no need to call the match callback again.

Link: https://lore.kernel.org/r/20210621201652.127611-2-u.kleine-koenig@pengutronix.de


Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
(cherry picked from commit e362547a)
Change-Id: Ic07137275f1e229a4318b328f9cf73b90bff7dad
Bug: 168585974
Signed-off-by: Will Deacon <willdeacon@google.com>