ASoC: soc-component.h: remove GPL explanation from header

soc-component.h already has SPDX License, thus, GPL explanation
is not needed. This patch removes it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/8736grafp5.wl-kuninori.morimoto.gx@renesas.com


Signed-off-by: Mark Brown <broonie@kernel.org>