drm/amdgpu/powerplay: fix sysfs_emit/sysfs_emit_at handling

sysfs_emit and sysfs_emit_at requrie a page boundary
aligned buf address. Make them happy!

v2: fix sysfs_emit -> sysfs_emit_at missed conversions

Cc: Lang Yu <lang.yu@amd.com>
Cc: Darren Powell <darren.powell@amd.com>
Fixes: 6db0c87a ("amdgpu/pm: Replace hwmgr smu usage of sprintf with sysfs_emit")
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1774


Reviewed-by: Lang Yu <lang.yu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>