drivers/dma: stm32: Don't omit IRQ status check

When checking for IRQ flags, we should also check
for IRQ status (IsEnabled ?).
If this is not done we can end up in Half Transfer
interrupt processing while it is not enabled.

Additionaly always use the id translation function
in LL API calls.

Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>