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_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[])
 {