ASoC: fsl: mpc8610_hpcd: Remove unused driver

ASoC: fsl: mpc8610_hpcd: Remove unused driver

The mpc8610_hpcd.c driver depends on CONFIG_MPC8610_HPCD which was
removed in commit 248667f8bbde ("powerpc: drop HPCD/MPC8610 evaluation
platform support"). That makes the driver unbuildable and unusable, so
remove it.

Depends-on: 248667f8bbde ("powerpc: drop HPCD/MPC8610 evaluation platform support")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20231122062712.2250426-1-mpe@ellerman.id.au
Signed-off-by: Mark Brown <broonie@kernel.org>