Create extra symbolic links at root for arm64 GSI

Relevant firmware/SW components have been moved out of directories
under root, but not all references to them updated. For example,
/vendor/firmware_mnt won't be used by Android to load firmware.
So we still need these symlinks so the firmware/SW components can
be accesses.

These links should be removed after all references are updated.

Bug: 111287060
Test: $ lunch aosp_arm64-userdebug; m -j
      # Checked $OUT/root for the added links
Change-Id: Ia7915dbdeabdee7a5cf8851772e89f080b927c45
diff --git a/target/board/generic_arm64/BoardConfig.mk b/target/board/generic_arm64/BoardConfig.mk
index 88f89de..caf0cee 100644
--- a/target/board/generic_arm64/BoardConfig.mk
+++ b/target/board/generic_arm64/BoardConfig.mk
@@ -63,9 +63,10 @@
 # Emulator system image is going to be used as GSI and some vendor still hasn't
 # cleaned up all device specific directories under root!
 
-# TODO(jiyong) These might be SoC specific.
-BOARD_ROOT_EXTRA_FOLDERS += firmware firmware/radio persist
+# TODO(b/111434759, b/111287060) SoC specific hacks
 BOARD_ROOT_EXTRA_SYMLINKS := /vendor/lib/dsp:/dsp
+BOARD_ROOT_EXTRA_SYMLINKS += /mnt/vendor/persist:/persist
+BOARD_ROOT_EXTRA_SYMLINKS += /vendor/firmware_mnt:/firmware
 
 # TODO(b/36764215): remove this setting when the generic system image
 # no longer has QCOM-specific directories under /.