AHCI: use a minimum of 1 block for trim ranges.

* Word 105 of ATA IDENTIFY should contain the maximum number of block
  ranges the device supports, but it always supports at least a single
  one.
* This change lets the trim command do something on Virtual Box.

src/add-ons/kernel/busses/scsi/ahci/ahci_port.cpp

@@ -623,6 +623,9 @@ AHCIPort::ScsiInquiry(scsi_ccb* request)
 			fUse48BitCommands, ataData.lba_sector_count,
 			ataData.lba48_sector_count, fSectorCount * fSectorSize);
 		if (fTrimSupported) {
+			if (fMaxTrimRangeBlocks == 0)
+				fMaxTrimRangeBlocks = 1;
+
 			bool deterministic = ataData.supports_deterministic_read_after_trim;
 			TRACE("trim supported, %" B_PRIu32 " ranges blocks, reads are "
 				"%sdeterministic%s.\n", fMaxTrimRangeBlocks,