syslinux: fix race issue

syslinux: fix race issue

Fixed do_install failed:
cp -r syslinux-6.01/com32/libupload/*.h image/usr/share/syslinux/com32/include/
[snip]
rm -rf image/usr/share/syslinux/com32/include
[snip]
cp: cannot create regular file `image/usr/share/syslinux/com32/include/serial.h': No such file or directory

The cp is happened in the "libupload" dir, while "rm -fr" is happend in
"lib" dir, let "libupload" depend "lib" will fix the problem.

(From OE-Core rev: 7df3b098278b6d5eb418af9dfe7fd2d3b3ea607c)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>