Increase LINE_LENGTH from 1024 to 2048 because nowadays for some
boards U-Boot CONFIG_SYS_CBSIZE (and CONFIG_SYS_PBSIZE respectively)
is greater than 1024. This leads to truncating longer lines which
can be fatal in specific cases, for example with a long bootcmd.

Signed-off-by: Leon Anavi <leon.anavi@konsulko.com>
Acked-by: Stefano Babic <stefano.babic@swupdate.org>