Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/arch/um/drivers/daemon_user.c b/arch/um/drivers/daemon_user.c
index 3695821..785baed 100644
--- a/arch/um/drivers/daemon_user.c
+++ b/arch/um/drivers/daemon_user.c
@@ -7,6 +7,7 @@
  */
 
 #include <stdint.h>
+#include <string.h>
 #include <unistd.h>
 #include <errno.h>
 #include <sys/types.h>