drm: bridge: samsung-dsim: Fix waiting for empty cmd transfer FIFO on older Exynos

drm: bridge: samsung-dsim: Fix waiting for empty cmd transfer FIFO on older Exynos

[ Upstream commit 15f389da11257b806da75a070cfa41ca0cc15aae ]

Samsung DSIM used in older Exynos SoCs (like Exynos 4210, 4x12, 3250)
doesn't report empty level of packer header FIFO. In case of those SoCs,
use the old way of waiting for empty command tranfsfer FIFO, removed
recently by commit 14806c641582 ("drm: bridge: samsung-dsim: Drain command transfer FIFO before transfer").

Fixes: 14806c641582 ("drm: bridge: samsung-dsim: Drain command transfer FIFO before transfer")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230809145641.3213210-1-m.szyprowski@samsung.com
Signed-off-by: Sasha Levin <sashal@kernel.org>