pxa: add support for palmtreo680 board

This patch adds support for the Palm Treo 680 smartphone.  A quick overview of
u-boot implementation on the treo 680...

The treo 680 has a Diskonchip G4 nand flash chip.  This device has a 2k region
that maps to the system bus at the reset vector in a NOR-like fashion so that it
can be used as the boot device.  The phone is shipped with this 2k region
configured as write-protected (can't be modified) and programmed with an initial
program loader (IPL).  At power-up, this IPL loads the contents of two flash
blocks to SDRAM and jumps to it.  The capacity of the two blocks is not large
enough to hold all of u-boot, so a u-boot SPL is used.  To conserve flash space,
these two blocks and the necessary number of subsequent blocks are programmed
with a concatenated spl + u-boot image.  That way, the IPL will also load a
portion of u-boot proper, and when the spl runs, it relocates the portion of
u-boot that the IPL has already loaded, and then resumes loading the remaining
part of u-boot before jumping to it.

The default_environment is used (CONFIG_ENV_IS_NOWHERE) because I didn't think
that having a writable environment was worth the cost of a flash block, although
adding it would be straightforward.  I abuse the CONFIG_EXTRA_ENV_SETTINGS
option to specify the usbtty for the console (CONFIG_SYS_CONSOLE_IS_IN_ENV).

Support for the LCD is included, but currently it is only useful for displaying
the u-boot splash screen.  But if u-boot is built without the usbtty console, it
does display the auto-boot progress nicely.

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
diff --git a/board/palmtreo680/Makefile b/board/palmtreo680/Makefile
new file mode 100644
index 0000000..34ffb99
--- /dev/null
+++ b/board/palmtreo680/Makefile
@@ -0,0 +1,34 @@
+#
+# Palm Treo680 Support
+#
+# Copyright (C) 2013 Mike Dunn <mikedunn@newsguy.com>
+#
+# This file is released under the terms of GPL v2 and any later version.
+# See the file COPYING in the root directory of the source tree for details.
+
+include $(TOPDIR)/config.mk
+
+LIB	= $(obj)lib$(BOARD).o
+
+COBJS	:= palmtreo680.o
+
+SRCS	:= $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+
+$(LIB):	$(obj).depend $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
+
+clean:
+	rm -f $(OBJS)
+
+distclean:	clean
+	rm -f $(LIB) core *.bak $(obj).depend
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################