nds32

With d53ecad9 some unused interrupt related code was removed.
However all of these options are currently unused.  Rather than migrate
some of these options to Kconfig we just remove the code in question.

The only related code changes here are that in some cases we use
CONFIG_STACKSIZE in non-IRQ related context.  In these cases we rename
and move the value local to the code in question.

Fixes: d53ecad9 ("Merge branch 'master' of git://git.denx.de/u-boot-sunxi"

)
Signed-off-by: Tom Rini <trini@konsulko.com>