Move platform-specific boot loader configuration into macros.

- fw/boot/boot.c (boot_loader): moved GTA-specific pull-up disable and
  I2C_SDA_PULL enable into macro PLATFORM_SETUP
- fw/boot/boot.c (run_payload): moved GTA-specific pull-up enable and
  I2C_SDA_PULL disable into macro PLATFORM_EXIT
- fw/boot/boot.c (boot_loader): moved GTA-specific I2C_SDA probe into macro
  PLATFORM_TEST
- fw/common/Makefile.common: removed all references to dependencies on
  .target. The caller is now responsible for these.
- fw/boot/dfu.c: don't include idbg/usb-ids.h; USB_VENDOR and USB_PRODUCT
  are now passed via macros

fw/common/Makefile.common

@@ -13,8 +13,7 @@
 
 CC=sdcc
 CFLAGS=--std-c99 -I. -I../common \
-       -DPAYLOAD_START=$(PAYLOAD_START) -DPAYLOAD_SIZE=$(PAYLOAD_SIZE) \
-       -D`cat ../.target`
+       -DPAYLOAD_START=$(PAYLOAD_START) -DPAYLOAD_SIZE=$(PAYLOAD_SIZE)
 LDFLAGS=--xram-size 1024
 
 
@@ -68,8 +67,6 @@ $(MAIN).ihx:	$(OBJS:%=%.rel)
 .c.rel:
 		$(CC) $(CFLAGS) -c $<
 
-$(OBJS:%=%.rel): ../.target
-
 # below, set dummy UART speed to make dependencies build without error
 
 depend .depend:	
@@ -81,8 +78,6 @@ depend .depend:
 		      { rm -f .depend; exit 1; }; \
 		done
 
-.depend:	../.target
-
 ifeq (.depend,$(wildcard .depend))
 include .depend
 endif