[media] solo6x10: fix 'dma from stack' warning

int solo_set_motion_block(struct solo_dev *solo_dev, u8 ch,

		const u16 *thresholds)

{

	const unsigned size = sizeof(u16) * 64;

	u32 off = SOLO_MOT_FLAG_AREA + ch * SOLO_MOT_THRESH_SIZE * 2;

	u16 buf[64];

	u16 *buf;

	int x, y;

	int ret = 0;

	memset(buf, 0, sizeof(buf));

	buf = kzalloc(size, GFP_KERNEL);

	for (y = 0; y < SOLO_MOTION_SZ; y++) {

		for (x = 0; x < SOLO_MOTION_SZ; x++)

			buf[x] = cpu_to_le16(thresholds[y * SOLO_MOTION_SZ + x]);

		ret |= solo_p2m_dma(solo_dev, 1, buf,

			SOLO_MOTION_EXT_ADDR(solo_dev) + off + y * sizeof(buf),

			sizeof(buf), 0, 0);

			SOLO_MOTION_EXT_ADDR(solo_dev) + off + y * size,

			size, 0, 0);

	}

	kfree(buf);

	return ret;

}