Add -j$(nproc) by default for make linux

After forgetfully running make without -j a couple of times,
fixing it once and for all.

Test: make runs faster, yay!
Change-Id: I9b62b1410a3b9261e62fc078ff8eed85bd02818a
1 file changed
tree: 779527baac368898d0fdb25cd7911ceb7df4aac8
  1. Makefile
  2. aarch64/
  3. common.inc
  4. kvm-unit-tests/