common/fdt_support.c: fix compile error

Fix build error introduced in beca5a5f

common/libcommon.a(fdt_support.o): In function `fdt_add_edid':
/local/hudson/jobs/mirrors-u-boot.git/workspace/common/fdt_support.c:1205: undefined reference to `fdt_increase_size'
make: *** [u-boot] Error 1

Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Anatolij Gustschin <agust@denx.de>