drm/nouveau/core: get rid of math.h, replace log2i with order_base_2

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --cc drivers/gpu/drm/nouveau/core/core/ramht.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/engine/fifo/nv50.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/engine/fifo/nv84.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/engine/fifo/nvc0.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/engine/fifo/nve0.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/include/core/math.h
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/os.h
Simple merge