ipq40xx: remove block- and pagesize from FB4040

This removes the block- and pagesize from the FritzBox 4040
image description, fixing incorrectly working sysupgrade.

With this commit, the default values for block- and pagesize are
used.

Signed-off-by: David Bauer <mail@david-bauer.net>
[chunkeey@gmail.com: removed 105-mtd-nor-add-mx25l25635f.patch as well]
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>