drivers/dma: stm32: don't omit IRQ status check in dma_is_irq_active

Fix stm32_dma_is_irq_active not checking the IRQ status(IsEnabled) for
active interrupts.
While the transfer-complete, half-transfer comp.  and transfer-error
is_XX_irq_active() functions check for IRQ status (IsEnabled),
ORing the result with dma_stm32_is_gi_active() overrides the
status check as gi is always 1 in case any of these flags is active.
Related to commit 96c92ed9.

Signed-off-by: Thomas Stranger <thomas.stranger@outlook.com>