drivers: dma: dma_lpc: fix bug with transfer size/width

Fix for bug:
https://github.com/zephyrproject-rtos/zephyr/issues/59802



The DMA controller only supports one transfer size, but
the Zephyr DMA driver api allows specifying a source_data_size
and dest_data_size which might be different. An old
version was always using dest_data_size for the transfer
size (variable is called "width"), but a recent change
made the driver use the MIN for the source and dest data
sizes. The MIN choice breaks the I2S driver because it
always set source_data_size to 1, but dest_data_size was
typically 4 for like two-channel 16-bit PCM data. So the
old driver worked using dest_data_size, but the new driver
broke I2S using MIN since source_data_size was 1.

To prevent confusion, change the DMA driver to assert that
source_data_size and dest_data_size are the same.

Also assert that the source_address and dest_address for
each block_config are properly aligned for the transfer size,
since that is a documentated requirement for the DMA controller.

Also rename max_xfer to max_xfer-bytes to be more clear what
the units are, and use this value in many places that
are comparing block_size in bytes rather than converting
block_size to words by dividing by width and
then comparing to NXP_LPC_DMA_MAX_XFER.

Signed-off-by: Mike J. Chen <mjchen@google.com>