drm/ttm: replace busy placement with flags v6

Instead of a list of separate busy placement add flags which indicate
that a placement should only be used when there is room or if we need to
evict.

v2: add missing TTM_PL_FLAG_IDLE for i915
v3: fix auto build test ERROR on drm-tip/drm-tip
v4: fix some typos pointed out by checkpatch
v5: cleanup some rebase problems with VMWGFX
v6: implement some missing VMWGFX functionality pointed out by Zack,
    rename the flags as suggested by Michel, rebase on drm-tip and
    adjust XE as well

Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Somalapuram Amaranath <Amaranath.Somalapuram@amd.com>
Reviewed-by: Zack Rusin <zack.rusin@broadcom.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240112125158.2748-4-christian.koenig@amd.com