drm/amd/display: Fix out-of-bounds read in dp_get_eq_aux_rd_interval()

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix out-of-bounds read in dp_get_eq_aux_rd_interval() [Why & How] The aux_rd_interval array in struct dc_lttpr_caps is declared with MAX_REPEATER_CNT - 1 (7) elements, indexed 0..6. However, the offset parameter passed to dp_get_eq_aux_rd_interval() can be as large as MAX_REPEATER_CNT (8) when a sink reports 8 LTTPR repeaters via DPCD. This leads to an out-of-bounds read of aux_rd_interval[7] when offset is 8. Fix this by growing aux_rd_interval to MAX_REPEATER_CNT elements to accommodate the full range of valid repeater counts defined by the DP spec. (cherry picked from commit a55a458a8df37a65ffda5cf721d554a8f74f6b04)