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/cow_user.c b/arch/um/drivers/cow_user.c
index 74b0c26..29b4658 100644
--- a/arch/um/drivers/cow_user.c
+++ b/arch/um/drivers/cow_user.c
@@ -17,6 +17,7 @@
 
 #define PATH_LEN_V1 256
 
+/* unsigned time_t works until year 2106 */
 typedef __u32 time32_t;
 
 struct cow_header_v1 {
@@ -197,7 +198,7 @@
 		     int sectorsize, int alignment, unsigned long long *size)
 {
 	struct cow_header_v3 *header;
-	unsigned long modtime;
+	long long modtime;
 	int err;
 
 	err = cow_seek_file(fd, 0);
@@ -276,7 +277,7 @@
 
 int read_cow_header(int (*reader)(__u64, char *, int, void *), void *arg,
 		    __u32 *version_out, char **backing_file_out,
-		    time_t *mtime_out, unsigned long long *size_out,
+		    long long *mtime_out, unsigned long long *size_out,
 		    int *sectorsize_out, __u32 *align_out,
 		    int *bitmap_offset_out)
 {
@@ -363,7 +364,7 @@
 
 		/*
 		 * this was used until Dec2005 - 64bits are needed to represent
-		 * 2038+. I.e. we can safely do this truncating cast.
+		 * 2106+. I.e. we can safely do this truncating cast.
 		 *
 		 * Additionally, we must use be32toh() instead of be64toh(), since
 		 * the program used to use the former (tested - I got mtime