ARM: netspace_v2: fix warnings

Fix compiler warnings when compiling for netspace_v2, netspace_max_v2
and inetspace_v2:

netspace_v2.c: In function 'board_early_init_f':
netspace_v2.c:37: warning: implicit declaration of function 'kw_config_gpio'
netspace_v2.c: In function 'board_init':
netspace_v2.c:86: warning: implicit declaration of function 'kw_sdram_bar'

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Simon Guinot <simon.guinot@sequanux.org>
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Acked-by: Marek Vasut <marek.vasut@gmail.com>