Add support for PCA953x I2C gpio devices

Initial support for NXP's 4 and 8 bit I2C gpio expanders
(eg pca9537, pca9557, etc). The CONFIG_PCA953X define
enables support for the devices while the CONFIG_CMD_PCA953X
define enables the pca953x command. The CONFIG_CMD_PCA953X_INFO
define enables an 'info' sub-command which provides summary
information for the given pca953x device.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
new file mode 100644
index 0000000..dd618ed
--- /dev/null
+++ b/drivers/gpio/Makefile
@@ -0,0 +1,47 @@
+#
+# Copyright 2000-2008
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+include $(TOPDIR)/config.mk
+
+LIB 	:= $(obj)libgpio.a
+
+COBJS-$(CONFIG_PCA953X)	+= pca953x.o
+
+COBJS	:= $(COBJS-y)
+SRCS 	:= $(COBJS:.o=.c)
+OBJS 	:= $(addprefix $(obj),$(COBJS))
+
+all:	$(LIB)
+
+$(LIB):	$(obj).depend $(OBJS)
+	$(AR) $(ARFLAGS) $@ $(OBJS)
+
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+########################################################################