Disable 2-pass partition search for speed 3

Moved disabling 2-pass partition search feature up from speed 4 to
speed 3.

AWCY result at speed 3:
 PSNR | PSNR Cb | PSNR Cr | PSNR HVS |   SSIM | MS SSIM | CIEDE 2000
0.0527|  0.1345 |  0.5060 |   0.2518 | 0.3566 |  0.3965 |     0.3204

Average encoder speedup at speed 3: 15.2%.
(Tested on 480p and 720p clips)

STATS_CHANGED

Change-Id: Ia95b91cfbfcc08d00d68541f08a0d10e526fb64e
diff --git a/build/cmake/aom_config_defaults.cmake b/build/cmake/aom_config_defaults.cmake
index 8b52860..f498acd 100644
--- a/build/cmake/aom_config_defaults.cmake
+++ b/build/cmake/aom_config_defaults.cmake
@@ -124,7 +124,7 @@
 set_aom_config_var(CONFIG_RD_DEBUG 0 NUMBER "AV1 experiment flag.")
 set_aom_config_var(CONFIG_2PASS_PARTITION_SEARCH_LVL_START 1 NUMBER
                    "AV1 experiment flag.")
-set_aom_config_var(CONFIG_2PASS_PARTITION_SEARCH_LVL_END 4 NUMBER
+set_aom_config_var(CONFIG_2PASS_PARTITION_SEARCH_LVL_END 3 NUMBER
                    "AV1 experiment flag.")
 set_aom_config_var(CONFIG_SHARP_SETTINGS 0 NUMBER "AV1 experiment flag.")
 set_aom_config_var(CONFIG_DISABLE_FULL_PIXEL_SPLIT_8X8 1 NUMBER