Kconfigs: Correct default of "0" on hex type entries

It is not a parse error to have a default value of "0" for a "hex" type
entry, instead of "0x0".  However, "0" and "0x0" are not treated the
same even by the tools themselves. Correct this by changing the default
value from "0" to "0x0" for all hex type questions that had the
incorrect default. Fix one instance (in two configs) of a default of "0"
being used on a hex question to be "0x0". Remove the cases where a
defconfig had set a value of "0x0" to be used as the default had been
"0".

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index e20c3a3..9d5df2c 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -568,7 +568,7 @@
 
 config DRAM_TPR3
 	hex "sunxi dram tpr3 value"
-	default 0
+	default 0x0
 	---help---
 	Set the dram controller tpr3 parameter. This parameter configures
 	the delay on the command lane and also phase shifts, which are
@@ -579,7 +579,7 @@
 
 config DRAM_DQS_GATING_DELAY
 	hex "sunxi dram dqs_gating_delay value"
-	default 0
+	default 0x0
 	---help---
 	Set the dram controller dqs_gating_delay parmeter. Each byte
 	encodes the DQS gating delay for each byte lane. The delay