Update USB U-Boot to v1.1.0 (#4)

* Update USB U-Boot to v1.1.0

* Add U-Boot Releaae Notes

RELEASE_NOTES.md

@@ -0,0 +1,56 @@
+# Astra U-Boot 2019.10 Release notes for Dolphin, Platypus and Myna2 RDK boards
+
+## 1. Information
+
+Base on U-Boot mainline version: U-Boot-2019.10
+
+## 2. Change Log
+### U-Boot-2019.10-Astra-v1.1.0
+Fastboot:
+
+	- Add "oem run" to support all U-Boot commands
+	- Add "flash ram" to download files into memory
+
+General:
+	- Support eMMC quick fill while upgrading sparse images
+
+### U-Boot-2019.10-Astra-v1.0.1
+mmc:
+
+	- Update eMMC & SDIO HW settings to work on all Astra board versions
+	- Add flag to force eMMC & SDIO to low speed
+
+General:
+
+	- SL1640: Fix environment saving issue on SPI flash
+
+### U-Boot-2019.10-Astra-v1.0.0
+General:
+
+	- Support USB2.0 device
+	- Support USB3.0 host
+	- Support Ethernet
+	- Support SPI Flash
+	- Support eMMC
+		- Support HS400 mode
+		- Boot Linux with SU-Boot
+	- Support SD card
+		- Support SDR104 mode
+		- Boot Linux with SU-Boot
+	- Support Image upgrading
+		- Support eMMC image upgrading in USB U-Boot, SPI U-Boot and SU-Boot
+			- USB U-Boot:  image via TFTP and USB slave (connect to PC)
+			- SPI U-Boot: image via TFTP and USB Host (connect to USB Disk)
+			- SU-Boot: image via TFTP and USB Host (connect to USB Disk)
+		- Support sparse image slices
+	- Support optee TA loading
+	- Support fastboot via UDP and USB2.0 (SPI U-Boot and SU-Boot)
+		- Supported commands:  reboot, flash
+
+## 3. Known issues
+### 3.1 Some USB disks can't be recognized in 1st probe
+fix: run command: "setenv usb_pgood_delay 1000;", can save on SPI U-Boot and SU-Boot by "saveenv"
+
+### 3.2 Some customer designed boards can't work with eMMC/SDIO high speed
+fix: run command: "setenv force_mmc_low_speed 1; setenv force_sd_low_speed 1;", can save on SPI U-Boot and SU-Boot by "saveenv"
+**This fix only works from v1.0.1**