esp.c: remove explicit setting of DRQ within ESP state machine

esp.c: remove explicit setting of DRQ within ESP state machine

Now the esp_update_drq() is called for all reads/writes to the FIFO, there is
no need to manually raise and lower the DRQ signal.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/611
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1831
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20240324191707.623175-18-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>