kmod-at86rf230 select REGMAP_SPI since 3.17, so add a dependency to
kmod-regmap.

Fixes the following error:

Package kmod-at86rf230 is missing dependencies for the following libraries:
regmap-core.ko
regmap-spi.ko

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@46387 3c298f89-4303-0410-b956-a3cf2f4a3e73