dm: test: Add tests for device's uclass platform data

This test introduces new test structure type:dm_test_perdev_uc_pdata.
The structure consists of three int values only. For the test purposes,
three pattern values are defined by enum, starting with TEST_UC_PDATA_INTVAL1.

This commit adds two test cases for uclass platform data:
- Test: dm_test_autobind_uclass_pdata_alloc - this tests if:
  * uclass driver sets: .per_device_platdata_auto_alloc_size field
  * the devices's: dev->uclass_platdata is non-NULL

- Test: dm_test_autobind_uclass_pdata_valid - this tests:
  * if the devices's: dev->uclass_platdata is non-NULL
  * the structure of type 'dm_test_perdev_uc_pdata' allocated at address
    pointed by dev->uclass_platdata. Each structure field, should be equal
    to proper pattern data, starting from .intval1 == TEST_UC_PDATA_INTVAL1.

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>