kconfig: remove useless 'default n'

kconfig bools are disabled by default, so specifying 'default n' is useless and
noisy. This patch removes all occurrences of 'default n'.

Signed-off-by: "Benoît THÉBAUDEAU" <benoit.thebaudeau@advansee.com>

 reporter_name="unknown"

 reporter_url="http://iphonelinux.org/index.php/Glibc_toolchain_using_crosstool-NG"

 reporter_comment="An (experimental) toolchain targeting the Apple's iPhone."