webos-image: jemalloc=12

:Release Notes:
Explicitly link with pthread

:Detailed Notes:
submissions/11..submissions/12
c35bf4 Explicitly link with pthread

:Testing Performed:
Only build tested.

:QA Notes:
No functional change to image

:Issues Addressed:
[BHV-7450] jemalloc: Explicitly link with pthread
[BHV-9296] CCC: jemalloc=12

Open-webOS-DCO-1.0-Signed-off-by: Andrii Motsok <andrii.motsok@lge.com>

Change-Id: Icc828e75e5b996cc76d2b089c47429cdd379bf79
Reviewed-on: https://g2g.palm.com/5627
Reviewed-by: DCO Verification
Reviewed-by: Susan Montooth <susan.montooth@lge.com>
Tested-by: Susan Montooth <susan.montooth@lge.com>