ASoC: tegra: Remove stale snd-soc-tegra-utils composite module definition

kconfiglint reports two warnings for sound/soc/tegra/Makefile:

M002: composite module 'snd-soc-tegra-utils' defined but not in any obj-*
M008: composite module 'snd-soc-tegra-utils': tegra_asoc_utils.o has no
source file

The composite module definition
`snd-soc-tegra-utils-y += tegra_asoc_utils.o` references a source file that
no longer exists and defines a module that is never included in any obj-*
target.

The tegra_asoc_utils module was originally introduced in commit
a3cd50deef7b ("ASoC: Tegra: Move utilities to separate module") by Stephen
Warren in 2011 to provide shared clock/rate utility functions for Tegra
machine drivers. At that time, the Makefile had both the composite
definition (`snd-soc-tegra-utils-objs`) and the build target
(`obj-$(CONFIG_SND_TEGRA_SOC) += snd-soc-tegra-utils.o`).

In 2021,
commit 8c1b3b159300 ("ASoC: tegra: Squash utils into common machine
driver")
by Dmitry Osipenko merged tegra_asoc_utils.c into tegra_asoc_machine.c,
deleting both the .c and .h files. That commit correctly removed the obj-*
build target line but overlooked the composite module definition line
(`snd-soc-tegra-utils-objs += tegra_asoc_utils.o`).

The orphaned line persisted unnoticed and was even mechanically updated in
2024 by
commit 51a50d6ad727 ("ASoC: tegra: Use *-y instead of *-objs in
Makefile")
by Takashi Iwai, which converted it from `-objs` to `-y` syntax as part of
a treewide cleanup — inadvertently refreshing a stale definition.

Remove the orphaned composite module definition since it serves no purpose:
the source file was deleted, the obj-* target was already removed, and the
functionality now lives in tegra_asoc_machine.c.

Assisted-by: Claude:claude-opus-4-6 kconfiglint
Signed-off-by: Sasha Levin <sashal@kernel.org>
Link: https://patch.msgid.link/20260426000249.54799-1-sashal@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>