ath10k: update QCA4019 firmware

With AVM Fritz!Box 4040 and OpenWrt 18.06 RC1 there are many kernel warnings
kern.warn kernel: [87771.917049] ath10k_ahb a000000.wifi: Invalid VHT mcs 15 peer stats
and there are disconnections when the connected clients are many, at the moment I tried with 16 clients on 2.4 GHz and 8 on 5 GHZ.

Firmware 10.4-3.5.3-00057 fixes these warnings and the problem of disconnections of some clients.

Signed-off-by: Massimo Tum <masnia@tiscali.it>

package/firmware/ath10k-firmware/Makefile

@@ -403,7 +403,7 @@ define Package/ath10k-firmware-qca4019/install
 		$(PKG_BUILD_DIR)/QCA4019/hw1.0/board-2.bin \
 		$(1)/lib/firmware/ath10k/QCA4019/hw1.0/
 	$(INSTALL_DATA) \
-		$(PKG_BUILD_DIR)/QCA4019/hw1.0/3.4/firmware-5.bin_10.4-3.4-00104 \
+		$(PKG_BUILD_DIR)/QCA4019/hw1.0/3.5.3/firmware-5.bin_10.4-3.5.3-00057 \
 		$(1)/lib/firmware/ath10k/QCA4019/hw1.0/firmware-5.bin
 endef