kernel: add missing symbol to 5.4 config

This symbol is exposed if KERNEL_PROVE_LOCKING is enabled.

Signed-off-by: Stijn Tintel <[email protected]>

target/linux/generic/config-5.4

@@ -4104,6 +4104,7 @@ CONFIG_PROC_SYSCTL=y
 # CONFIG_PROFILING is not set
 # CONFIG_PROVE_LOCKING is not set
 # CONFIG_PROVE_RCU is not set
+# CONFIG_PROVE_RCU_LIST is not set
 # CONFIG_PROVE_RCU_REPEATEDLY is not set
 # CONFIG_PSAMPLE is not set
 # CONFIG_PSB6970_PHY is not set