media: exynos4-is: fix kernel-doc warnings

media: exynos4-is: fix kernel-doc warnings

Fix those kernel-doc warnings:

    drivers/media/platform/exynos4-is/mipi-csis.c:229: warning: No description found for parameter 'clk_frequency'
    drivers/media/platform/exynos4-is/mipi-csis.c:229: warning: Excess struct member 'clock_frequency' description in 'csis_state'
    drivers/media/platform/exynos4-is/media-dev.c:69: warning: No description found for parameter 'p'
    drivers/media/platform/exynos4-is/media-dev.c:160: warning: No description found for parameter 'p'
    drivers/media/platform/exynos4-is/media-dev.c:160: warning: No description found for parameter 'on'
    drivers/media/platform/exynos4-is/media-dev.c:160: warning: Excess function parameter 'fimc' description in 'fimc_pipeline_s_power'
    drivers/media/platform/exynos4-is/media-dev.c:160: warning: Excess function parameter 'state' description in 'fimc_pipeline_s_power'
    drivers/media/platform/exynos4-is/media-dev.c:229: warning: No description found for parameter 'ep'
    drivers/media/platform/exynos4-is/media-dev.c:260: warning: No description found for parameter 'ep'
    drivers/media/platform/exynos4-is/media-dev.c:260: warning: Excess function parameter 'fimc' description in '__fimc_pipeline_close'
    drivers/media/platform/exynos4-is/media-dev.c:288: warning: No description found for parameter 'ep'
    drivers/media/platform/exynos4-is/media-dev.c:288: warning: Excess function parameter 'pipeline' description in '__fimc_pipeline_s_stream'
    drivers/media/platform/exynos4-is/media-dev.c:916: warning: No description found for parameter 'fmd'
    drivers/media/platform/exynos4-is/fimc-capture.c:155: warning: No description found for parameter 'ctx'
    drivers/media/platform/exynos4-is/fimc-capture.c:868: warning: No description found for parameter 'num_planes'
    drivers/media/platform/exynos4-is/fimc-capture.c:1108: warning: No description found for parameter 'fimc'

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>