ASoC: amd: acp: Drop superfluous assignment in acp_sof_probe()

The 'card' pointer is not required to be NULL initialized as it is never
accessed before the related memory allocation takes place.

Drop the redundant assignment.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Link: https://patch.msgid.link/20250429-acp-sof-probe-assign-v1-1-9784f6eb7660@collabora.com


Signed-off-by: Mark Brown <broonie@kernel.org>