Convert CONFIG_TRACE_BUFFER_SIZE et al to Kconfig

This converts the following to Kconfig:
   CONFIG_TRACE_BUFFER_SIZE
   CONFIG_TRACE_EARLY_SIZE
   CONFIG_TRACE_EARLY
   CONFIG_TRACE_EARLY_ADDR

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/Kconfig b/lib/Kconfig
index a3352a4..05f82d4 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -174,6 +174,54 @@
 	  memory for exporting for analysis (e.g. using bootchart).
 	  See doc/README.trace for full details.
 
+config TRACE_BUFFER_SIZE
+	hex "Size of trace buffer in U-Boot"
+	depends on TRACE
+	default 0x01000000
+	help
+	  Sets the size of the trace buffer in U-Boot. This is allocated from
+	  memory during relocation. If this buffer is too small, the trace
+	  history will be truncated, with later records omitted.
+
+	  If early trace is enabled (i.e. before relocation), this buffer must
+	  be large enough to include all the data from the early trace buffer as
+	  well, since this is copied over to the main buffer during relocation.
+
+	  A trace record is emitted for each function call and each record is
+	  12 bytes (see struct trace_call). A suggested minimum size is 1MB. If
+	  the size is too small then 'trace stats' will show a message saying
+	  how many records were dropped due to buffer overflow.
+
+config TRACE_EARLY
+	bool "Enable tracing before relocation"
+	depends on TRACE
+	help
+	  Sometimes it is helpful to trace execution of U-Boot before
+	  relocation. This is possible by using a arch-specific, fixed buffer
+	  position in memory. Enable this option to start tracing as early as
+	  possible after U-Boot starts.
+
+config TRACE_EARLY_SIZE
+	hex "Size of early trace buffer in U-Boot"
+	depends on TRACE_EARLY
+	default 0x00100000
+	help
+	  Sets the size of the early trace buffer in bytes. This is used to hold
+	  tracing information before relocation.
+
+config TRACE_EARLY_ADDR
+	hex "Address of early trace buffer in U-Boot"
+	depends on TRACE_EARLY
+	default 0x00100000
+	help
+	  Sets the address of the early trace buffer in U-Boot. This memory
+	  must be accessible before relocation.
+
+	  A trace record is emitted for each function call and each record is
+	  12 bytes (see struct trace_call). A suggested minimum size is 1MB. If
+	  the size is too small then the message which says the amount of early
+	  data being coped will the the same as the
+
 source lib/dhry/Kconfig
 
 menu "Security support"