Use correct spelling of "U-Boot"

Correct spelling of "U-Boot" shall be used in all written text
(documentation, comments in source files etc.).

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/doc/README.fsl-ddr b/doc/README.fsl-ddr
index 1243a12..cd71ec8 100644
--- a/doc/README.fsl-ddr
+++ b/doc/README.fsl-ddr
@@ -61,7 +61,7 @@
 	 "hwconfig=fsl_ddr:ctlr_intlv=bank"			\
 	 ......
 
-2. Run u-boot "setenv" command to configure the memory interleaving mode.
+2. Run U-Boot "setenv" command to configure the memory interleaving mode.
    Either numerical or string value is accepted.
 
   # disable memory controller interleaving
@@ -125,7 +125,7 @@
 
 Memory testing options for mpc85xx
 ==================================
-1. Memory test can be done once U-boot prompt comes up using mtest, or
+1. Memory test can be done once U-Boot prompt comes up using mtest, or
 2. Memory test can be done with Power-On-Self-Test function, activated at
    compile time.
 
@@ -267,7 +267,7 @@
 be activated by setting the environment variable "ddr_interactive" to any
 value.  (The value of ddr_interactive may have a meaning in the future, but,
 for now, the presence of the variable will cause the debugger to run.)  Once
-activated, U-boot will show the prompt "FSL DDR>" before enabling the DDR
+activated, U-Boot will show the prompt "FSL DDR>" before enabling the DDR
 controller.  The available commands are printed by typing "help".
 
 Another way to enter the interactive DDR debugger without setting the
@@ -275,7 +275,7 @@
 process.  To save booting time, no additional delay is added, so the window
 to send the key press is very short -- basically, it is the time before the
 memory controller code starts to run.  For example, when rebooting from
-within u-boot, the user must press 'd' IMMEDIATELY after hitting enter to
+within U-Boot, the user must press 'd' IMMEDIATELY after hitting enter to
 initiate a 'reset' command.  In case of power on/reset, the user can hold
 down the 'd' key while applying power or hitting the board's reset button.
 
@@ -341,7 +341,7 @@
 	no argument	- print a list of all commands
 
 go
-	no argument	- program memory controller(s) and continue with U-boot
+	no argument	- program memory controller(s) and continue with U-Boot
 
 Examples of debugging flow