ATAD: fix device probing for slave device

[pcm720]

This PR fixes device probing for ATA slave device in ata_init_devices.

ata_device_probe writes to ATA registers after checking nsector, sector, hcyl and lcyl values:

ps2sdk/iop/dev9/atad/src/ps2atad.c

Lines 1204 to 1207 in f388f51

	ata_hwport->r_lcyl = 0x55;
	ata_hwport->r_hcyl = 0xaa;
	lcyl = ata_hwport->r_lcyl & 0xff;
	hcyl = ata_hwport->r_hcyl & 0xff;

As it turns out, simply switching from device 0 to device 1 does not clear the ATA controller register values. This causes probing for device 1 to reuse register values from the previous ata_device_probe call.

Resetting the ATA controller before calling ata_device_select fixes this.

Before the change, device 1 was ignored.
After the change, probing correctly handles all cases, including setups with a missing master device.

  hdd: disk0: 0x07744000 sectors, max 0x00200000
  hdd: disk1: 0x01dd7fb0 sectors, max 0x00080000
  hdd: drive status 0, format version 00000002
  hdd: drive status 0, format version 00000002
  hdd: version 0205 driver start. This is OSD version!
  pfs Playstation Filesystem Driver v2.2
ps2fs: (c) 2003 Sjeep, V  ector and Florin Sasu
  pfs Max mount: 4, Max open: 10, Number of buffers: 40
  pfs version 0202 driver start.
  Checking APA header for HDD0: 0
  Checking APA header for HDD1: 0
  hdd0 partitions:
        __mbr
        __net
        __system
        __sysconf
        __common
        __.POPS
  hdd1 partitions:
        __mbr
        __net
        __system
        __sysconf
        __common
        PP.SLUS-20002..RIDGE_RACER_V
        PP.SLUS-20002..RIDGE_RACER_V
        PP.SLUS-20002..RIDGE_RACER_V
  Mounting hdd0:__common to pfs0: 0
  Mounting hdd1:__common to pfs0: 0