bios_emulator: Add an option to enable debugging

At present there are DEBUG options spread around the place. If you enable
one and not another you can end up with an emulator that does not work,
since each file can have a different view of what the registers look like.
To fix this, create a global CONFIG_X86EMU_DEBUG option that keeps
everything consistent.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/bios_emulator/include/x86emu/debug.h b/drivers/bios_emulator/include/x86emu/debug.h
index 268c9d3..12d6c7f 100644
--- a/drivers/bios_emulator/include/x86emu/debug.h
+++ b/drivers/bios_emulator/include/x86emu/debug.h
@@ -48,7 +48,7 @@
 #define CHECK_MEM_ACCESS_F		0x4	/*using regular linear pointer */
 #define CHECK_DATA_ACCESS_F		0x8	/*using segment:offset */
 
-#ifdef DEBUG
+#ifdef CONFIG_X86EMU_DEBUG
 # define CHECK_IP_FETCH()		(M.x86.check & CHECK_IP_FETCH_F)
 # define CHECK_SP_ACCESS()		(M.x86.check & CHECK_SP_ACCESS_F)
 # define CHECK_MEM_ACCESS()		(M.x86.check & CHECK_MEM_ACCESS_F)
@@ -60,7 +60,7 @@
 # define CHECK_DATA_ACCESS()
 #endif
 
-#ifdef DEBUG
+#ifdef CONFIG_X86EMU_DEBUG
 # define DEBUG_INSTRUMENT()	(M.x86.debug & DEBUG_INSTRUMENT_F)
 # define DEBUG_DECODE()		(M.x86.debug & DEBUG_DECODE_F)
 # define DEBUG_TRACE()		(M.x86.debug & DEBUG_TRACE_F)
@@ -99,7 +99,7 @@
 # define DEBUG_DECODE_NOPRINT() 0
 #endif
 
-#ifdef DEBUG
+#ifdef CONFIG_X86EMU_DEBUG
 
 # define DECODE_PRINTF(x)	if (DEBUG_DECODE()) \
 				    x86emu_decode_printf(x)
@@ -129,7 +129,7 @@
 # define SAVE_IP_CS(x,y)
 #endif
 
-#ifdef DEBUG
+#ifdef CONFIG_X86EMU_DEBUG
 #define TRACE_REGS()					    \
     if (DEBUG_DISASSEMBLE()) {				    \
 	x86emu_just_disassemble();			    \
@@ -140,7 +140,7 @@
 # define TRACE_REGS()
 #endif
 
-#ifdef DEBUG
+#ifdef CONFIG_X86EMU_DEBUG
 # define SINGLE_STEP()	    if (DEBUG_STEP()) x86emu_single_step()
 #else
 # define SINGLE_STEP()
@@ -150,7 +150,7 @@
     TRACE_REGS();	    \
     SINGLE_STEP()
 
-#ifdef DEBUG
+#ifdef CONFIG_X86EMU_DEBUG
 # define START_OF_INSTR()
 # define END_OF_INSTR()	    EndOfTheInstructionProcedure: x86emu_end_instr();
 # define END_OF_INSTR_NO_TRACE()    x86emu_end_instr();
@@ -160,7 +160,7 @@
 # define END_OF_INSTR_NO_TRACE()
 #endif
 
-#ifdef DEBUG
+#ifdef CONFIG_X86EMU_DEBUG
 # define  CALL_TRACE(u,v,w,x,s)					\
     if (DEBUG_TRACECALLREGS())					\
 	x86emu_dump_regs();					\
@@ -176,7 +176,7 @@
 # define RETURN_TRACE(n,u,v)
 #endif
 
-#ifdef DEBUG
+#ifdef CONFIG_X86EMU_DEBUG
 #define DB(x)	x
 #else
 #define DB(x)