drivers/opp: Remove "select SRCU"

Now that the SRCU Kconfig option is unconditionally selected, there is
no longer any point in selecting it.  Therefore, remove the "select SRCU"
Kconfig statements.

Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Viresh Kumar <[email protected]>
Cc: Nishanth Menon <[email protected]>
Cc: Stephen Boyd <[email protected]>
Cc: <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>

Author: paulmckrcu

drivers/opp/Kconfig

@@ -1,7 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config PM_OPP
 	bool
-	select SRCU
 	help
 	  SOCs have a standard set of tuples consisting of frequency and
 	  voltage pairs that the device will support per voltage domain. This