mtd: drop unconditional non LFS build

Buildroot removed non LFS support in the 2015.05 release. We now pass
-D_FILE_OFFSET_BITS=64 unconditionally, so the mtd WITHOUT_LARGEFILE make
variable has no effect.

[Thomas: keep using += for other assigments of MTD_MAKE_OPTS.]

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/mtd/mtd.mk

@@ -24,8 +24,6 @@ ifeq ($(BR2_PACKAGE_BUSYBOX),y)
 MTD_DEPENDENCIES += busybox
 endif
 
-MTD_MAKE_OPTS = WITHOUT_LARGEFILE=1
-
 # If extended attributes are required, the acl package must
 # also be enabled which will also include the attr package.
 ifeq ($(BR2_PACKAGE_ACL),y)