We need to explicitly set the TLB Request Timer initial value in the
BW_BUDDY registers to 0x8 rather than relying on the hardware default.

v2: Apply missing REG_FIELD_PREP to ensure 0x8 is placed in the correct
    bits during the rmw.  (Jose)

Bspec: 52890
Bspec: 50044
Fixes: 3fa01d64 ("drm/i915/tgl: Program BW_BUDDY registers during display init")
Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200219215655.2923650-1-matthew.d.roper@intel.comReviewed-by: José Roberto de Souza <jose.souza@intel.com>