[build] Avoid spurious "make clean" when building for the first time

[build] Avoid spurious "make clean" when building for the first time

The function trace recorder build logic defaults to making "clean" a
dependency of the first build in a clean checkout.  This is redundant
and causes problems if the build process spins up multiple make
invocations to handle multiple build architectures.

Fix by replacing with logic based on the known-working patterns used
for the ASSERT and PROFILE build parameters.

Signed-off-by: Michael Brown <mcb30@ipxe.org>