tests: drivers: adc: adc_api: add dma test

Move ADC DMA tests directly into adc_api test for Kinetis and STM32 boards.
Needs to disable CONFIG_TEST_USERSPACE for this subtest because of caching
issue for STM32H7 (as it was done dor adc_dma test).

Signed-off-by: Guillaume Gautier <guillaume.gautier-ext@st.com>