Revert "axolotl-shiftos: disable mainline modules"

This reverts commit d19747409d9a3c4e5e733a3493eac7c3281adbfe.

We have upgraded to mainline_t_2023_jan_t1005588, which restores
support for 4.9 kernels.

Change-Id: Iedba9c6e36e3fe7c877e5f5047babc7153a863b9
Signed-off-by: Alexander Martinz <amartinz@shiftphones.com>
diff --git a/axolotl.mk b/axolotl.mk
index ce8053c..b40c779 100644
--- a/axolotl.mk
+++ b/axolotl.mk
@@ -53,7 +53,7 @@
 else
 GMS_MAKEFILE := gms_eea_v2_type4c_64bit_only.mk
 endif
-#MAINLINE_MODULES_MAKEFILE := mainline_modules.mk
+MAINLINE_MODULES_MAKEFILE := mainline_modules.mk
 
 # Widevine
 PRODUCT_PACKAGES += \