Revert "[ARM] 4642/2: netX: default config for netx based boards"

This reverts commit f33bac8, which was
totally bogus.

The arm/configs/netx_defconfig file already existed - in the right
place. Namely under "arch".

Noticed-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Robert Schwebel <r.schwebel@pengutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>