kbuild: refactor single builds of *.ko

[ Upstream commit f110e5a2 ]

Remove the potentially invalid modules.order instead of using
the temporary file.

Also, KBUILD_MODULES is don't care for single builds. No need to
cancel it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Stable-dep-of: ed1f4ccf ("clk: imx: imx8mp: add shared clk gate for usb suspend clk")
Signed-off-by: Sasha Levin <sashal@kernel.org>