[source] kernel: enable CONFIG_ADVISE_SYSCALLS

[LEDE Commits]

jow pushed a commit to source.git, branch master:
https://git.lede-project.org/56342ee2bcbf9bf8918a01045471c7bb7faa1596

commit 56342ee2bcbf9bf8918a01045471c7bb7faa1596
Author: Rosen Penev <rosenp at gmail.com>
AuthorDate: Sat Oct 14 17:07:19 2017 -0700

    kernel: enable CONFIG_ADVISE_SYSCALLS
    
    Without this, posix_[fm]advise does not work. This causes issues with
    btrfs-progs, which uses fadvise to drop caches.
    
    Signed-off-by: Rosen Penev <rosenp at gmail.com>
---
 target/linux/generic/config-4.9 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/linux/generic/config-4.9 b/target/linux/generic/config-4.9
index 4d2c911..9512e49 100644
--- a/target/linux/generic/config-4.9
+++ b/target/linux/generic/config-4.9
@@ -90,7 +90,7 @@ CONFIG_32BIT=y
 # CONFIG_ADM6996_PHY is not set
 # CONFIG_ADM8211 is not set
 # CONFIG_ADT7316 is not set
-# CONFIG_ADVISE_SYSCALLS is not set
+CONFIG_ADVISE_SYSCALLS=y
 # CONFIG_ADXRS450 is not set
 CONFIG_AEABI=y
 # CONFIG_AFE4403 is not set