UPSTREAM: kbuild: replace sed with $(subst ) or $(patsubst )

For simple text replacement, it is better to use a built-in function
instead of sed if possible. You can save one process forking.

I do not mean to replace all sed invocations because GNU Make itself
does not support regular expression (unless you use guile).

I just replaced simple ones.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
(cherry picked from commit 6e0839fd)
Bug: 209655537
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Change-Id: I92c893dfb17055db0b8a8ca2f39ddfa5f31a118d