kmod-sched-cake: bump to latest cake

This bumps to the latest & possibly greatest cake, sadly it's still
inedible but from an SQM point of view quite tasty :-)

Main tweaks since previous bump, improved ack_filter, some extra stats,
support for 64bit netlink parameters (higher rates/byte counters)

0520a6c Fix NAT option handling
8da93e1 Make sure we always call qdisc_watchdog_init() in cake_init()
f65daf6 Fix mismatched parenthesis
51d4ab3 Change flag handling to be safe even when mixing with non-eligible ACKs
f2ea091 ack_filter: protect DCTCP with stricter filtering of ECE marks
28b4560 ACK filter: Handle wrapping sequence numbers and DSACKs
73f62d9 Use the right PAD attribute for options
5969c14 Use 32 for tin backlog
e289f31 Move all the u64 netlink attributes together
36180a0 Check ACK seqno before parsing SACKs
91bbc01 Merge branch 'mine' into cobalt
58c55ec Rework SACK check to compare the ranges of two SACKs
9a5d593 ack_filter: Add proper handling of SACKs
eca95d4 ack_filter: short-circuit TCP flag check
d50a246 compat: backport some ktime functions
7b7ad11 compat: define tcpopt_fastopen for pre-4.1 kernels
ca54cdb Fix ktime compare
9d7dcc0 ack filter: Parse TCP options and only drop safe ones
b119882 Return EOPNOTSUPP on NAT option if conntrack is not available
842d7f0 Don't try to pad stats with tin_stats padding
bd46dc2 Use 64-bit divide helper
8e41bf0 Make sure we never drop SACKs when filtering ACKs
66e5d60 Avoid comparing ktime_t to scalar values
7fab017 Actually commit the ktime_t changes
fca6d13 Switch to ktime_t and get rid of cobalt.h
6f7e5af Can't use do_div with 64-bit divisors

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>

package/kernel/kmod-sched-cake/Makefile

@@ -13,9 +13,9 @@ PKG_RELEASE:=1
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://github.com/dtaht/sch_cake.git
-PKG_SOURCE_DATE:=2018-05-15
-PKG_SOURCE_VERSION:=779e91a91e803cf2b95a6a46de721d3a4fd4dfe6
-PKG_MIRROR_HASH:=2bd1e9aee6d53a2a140ad5ece6d8eeccbfb8ae8c788e84f9dd946e29abb64010
+PKG_SOURCE_DATE:=2018-06-26
+PKG_SOURCE_VERSION:=0520a6cbcce759b109568b26df3b6081aed42483
+PKG_MIRROR_HASH:=9f89c0006274e8b2004e8d22bf0d02fdf93194b4ff8753ac6cdd7cc48ce7305e
 PKG_MAINTAINER:=Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
 
 include $(INCLUDE_DIR)/package.mk