esp.c: only raise IRQ in esp_transfer_data() for CMD_SEL, CMD_SELATN and CMD_TI commands

esp.c: only raise IRQ in esp_transfer_data() for CMD_SEL, CMD_SELATN and CMD_TI commands

Clarify the logic in esp_transfer_data() to ensure that the deferred interrupt code
can only be triggered for CMD_SEL, CMD_SELATN and CMD_TI commands. This should already
be the case, but make it explicit to ensure the logic isn't triggered unexpectedly.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20250711204636.542964-2-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>