Make SCSI disk support built into kernel

A previous patch try to make SCSI support and USB mass storage
support built-in kernel. but this option was omitted in it.
This omission cause usb disk can not be probed correctly and
udev doesn't work on usb mass storage devices.

arch/arm/configs/ntosd_644xA_defconfig

@@ -563,7 +563,7 @@ CONFIG_SCSI_PROC_FS=y
 #
 # SCSI support type (disk, tape, CD-ROM)
 #
-CONFIG_BLK_DEV_SD=m
+CONFIG_BLK_DEV_SD=y
 # CONFIG_CHR_DEV_ST is not set
 # CONFIG_CHR_DEV_OSST is not set
 # CONFIG_BLK_DEV_SR is not set