drm/gma500/power: Fix a bunch of *dev documentation issues

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

 drivers/gpu/drm/gma500/power.c:101: warning: Function parameter or member 'pdev' not described in 'gma_resume_display'
 drivers/gpu/drm/gma500/power.c:155: warning: Function parameter or member 'pdev' not described in 'gma_resume_pci'
 drivers/gpu/drm/gma500/power.c:155: warning: Excess function parameter 'dev' description in 'gma_resume_pci'
 drivers/gpu/drm/gma500/power.c:189: warning: Function parameter or member '_dev' not described in 'gma_power_suspend'
 drivers/gpu/drm/gma500/power.c:189: warning: Excess function parameter 'pdev' description in 'gma_power_suspend'
 drivers/gpu/drm/gma500/power.c:189: warning: Excess function parameter 'state' description in 'gma_power_suspend'
 drivers/gpu/drm/gma500/power.c:216: warning: Function parameter or member '_dev' not described in 'gma_power_resume'
 drivers/gpu/drm/gma500/power.c:216: warning: Excess function parameter 'pdev' description in 'gma_power_resume'

Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Benjamin Defnet <benjamin.r.defnet@intel.com>
Cc: Rajesh Poornachandran <rajesh.poornachandran@intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210115181313.3431493-20-lee.jones@linaro.org