ASoC: cs-amp-lib-test: Add test for getting cal data from HP EFI

ASoC: cs-amp-lib-test: Add test for getting cal data from HP EFI

Add a test case that cs_amp_get_efi_calibration_data() returns data
when it is in the HP-specific EFI variable.

This uses redirected implementation of cs_amp_get_efi_variable() that
only returns data if the passes name and GUID match the HP EFI variable.
A simple test case installs this function hook and then checks that
calibration data is returned.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Message-ID: <20250909113039.922065-7-rf@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>