disk/part.c: Make features optional

If we don't want to build support for any partition types we can now
add #undef CONFIG_PARTITIONS in a board config file to keep this from
being compiled in. Otherwise boards assume this is compiled in by
default

Signed-off-by: Matthew McClintock <msm@freescale.com>
diff --git a/common/cmd_ide.c b/common/cmd_ide.c
index 7fbc053..2e8c6e0 100644
--- a/common/cmd_ide.c
+++ b/common/cmd_ide.c
@@ -719,10 +719,12 @@
 
 /* ------------------------------------------------------------------------- */
 
+#ifdef CONFIG_PARTITIONS
 block_dev_desc_t * ide_get_dev(int dev)
 {
 	return (dev < CONFIG_SYS_IDE_MAXDEVICE) ? &ide_dev_desc[dev] : NULL;
 }
+#endif
 
 
 #ifdef CONFIG_IDE_8xx_DIRECT
diff --git a/common/cmd_sata.c b/common/cmd_sata.c
index 7efa859..f62c0cb 100644
--- a/common/cmd_sata.c
+++ b/common/cmd_sata.c
@@ -57,10 +57,12 @@
 }
 int sata_initialize(void) __attribute__((weak,alias("__sata_initialize")));
 
+#ifdef CONFIG_PARTITIONS
 block_dev_desc_t *sata_get_dev(int dev)
 {
 	return (dev < CONFIG_SYS_SATA_MAX_DEVICE) ? &sata_dev_desc[dev] : NULL;
 }
+#endif
 
 int do_sata(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
diff --git a/common/cmd_scsi.c b/common/cmd_scsi.c
index 8e8e930..fa10751 100644
--- a/common/cmd_scsi.c
+++ b/common/cmd_scsi.c
@@ -194,11 +194,12 @@
 }
 #endif
 
+#ifdef CONFIG_PARTITIONS
 block_dev_desc_t * scsi_get_dev(int dev)
 {
 	return (dev < CONFIG_SYS_SCSI_MAX_DEVICE) ? &scsi_dev_desc[dev] : NULL;
 }
-
+#endif
 
 /******************************************************************************
  * scsi boot command intepreter. Derived from diskboot
diff --git a/common/usb_storage.c b/common/usb_storage.c
index 9ecf165..16667f3 100644
--- a/common/usb_storage.c
+++ b/common/usb_storage.c
@@ -173,11 +173,12 @@
 struct usb_device * usb_get_dev_index(int index);
 void uhci_show_temp_int_td(void);
 
+#ifdef CONFIG_PARTITIONS
 block_dev_desc_t *usb_stor_get_dev(int index)
 {
 	return (index < usb_max_devs) ? &usb_dev_desc[index] : NULL;
 }
-
+#endif
 
 void usb_show_progress(void)
 {