drm/radeon/radeon_display: Fix function doc formatting and missing param issues

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/radeon/radeon_display.c:264: warning: Function parameter or member '__work' not described in 'radeon_unpin_work_func'
 drivers/gpu/drm/radeon/radeon_display.c:406: warning: Function parameter or member '__work' not described in 'radeon_flip_work_func'
 drivers/gpu/drm/radeon/radeon_display.c:956: warning: Function parameter or member 'freq' not described in 'radeon_compute_pll_avivo'
 drivers/gpu/drm/radeon/radeon_display.c:956: warning: Function parameter or member 'fb_div_p' not described in 'radeon_compute_pll_avivo'
 drivers/gpu/drm/radeon/radeon_display.c:956: warning: Function parameter or member 'frac_fb_div_p' not described in 'radeon_compute_pll_avivo'
 drivers/gpu/drm/radeon/radeon_display.c:956: warning: Function parameter or member 'ref_div_p' not described in 'radeon_compute_pll_avivo'
 drivers/gpu/drm/radeon/radeon_display.c:956: warning: Function parameter or member 'post_div_p' not described in 'radeon_compute_pll_avivo'

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: report to <xorg-driver-ati@lists.x.org>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_display.c

@@ -256,7 +256,7 @@ static void radeon_crtc_destroy(struct drm_crtc *crtc)
 /**
  * radeon_unpin_work_func - unpin old buffer object
  *
- * @__work - kernel work item
+ * @__work: kernel work item
  *
  * Unpin the old frame buffer object outside of the interrupt handler
  */
@@ -398,7 +398,7 @@ void radeon_crtc_handle_flip(struct radeon_device *rdev, int crtc_id)
 /**
  * radeon_flip_work_func - page flip framebuffer
  *
- * @work - kernel work item
+ * @__work: kernel work item
  *
  * Wait for the buffer object to become idle and do the actual page flip
  */
@@ -937,11 +937,12 @@ static void avivo_get_fb_ref_div(unsigned nom, unsigned den, unsigned post_div,
  * radeon_compute_pll_avivo - compute PLL paramaters
  *
  * @pll: information about the PLL
+ * @freq: target frequency
  * @dot_clock_p: resulting pixel clock
- * fb_div_p: resulting feedback divider
- * frac_fb_div_p: fractional part of the feedback divider
- * ref_div_p: resulting reference divider
- * post_div_p: resulting reference divider
+ * @fb_div_p: resulting feedback divider
+ * @frac_fb_div_p: fractional part of the feedback divider
+ * @ref_div_p: resulting reference divider
+ * @post_div_p: resulting reference divider
  *
  * Try to calculate the PLL parameters to generate the given frequency:
  * dot_clock = (ref_freq * feedback_div) / (ref_div * post_div)