drm/amd/display: Revert "Fix conversions between bytes and KB"

[Why & How]
HostVMMinPageSize is expected to be in KB according to spec,
the checks later down the line reflect this as well.

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Taimur Hassan <syed.hassan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>