ahci: print the number of implemented ports

ahci: print the number of implemented ports

We are currently printing the CAP.NP field.
CAP.NP is a 0's based value indicating the maximum number of ports
supported by the HBA silicon. Note that the number of ports indicated
in this field may be more than the number of ports indicated in the
PI (ports implemented) register. (See AHCI 1.3.1, section 3.1.1 -
Offset 00h: CAP – HBA Capabilities.)

PI (ports implemented) register is a field that has a bit set to '1'
if that specific port is implemented. This register is allowed to have
zeroes mixed with ones, i.e. a port in the middle is allowed to be
unimplemented. (See AHCI 1.3.1, section 3.1.4 - Offset 0Ch: PI – Ports
Implemented.)

Since the number of ports implemented might be smaller than the maximum
number of ports supported by the HBA silicon, print the number of
implemented ports as well.

While at it, clarify the properties being printed, and add a separator
(,), as that is currently missing, making it very easy to get confused
if the number before or after <property> belongs to <property>.

before:
ahci 0000:00:03.0: masking port_map 0x3f -> 0x2f
ahci 0000:00:03.0: AHCI 0001.0000 32 slots 6 ports 1.5 Gbps 0x2f impl SATA mode
ahci 0000:00:03.0: flags: 64bit ncq only

after:
ahci 0000:00:03.0: masking port_map 0x3f -> 0x2f
ahci 0000:00:03.0: AHCI vers 0001.0000, 32 command slots, 1.5 Gbps, SATA mode
ahci 0000:00:03.0: 5/6 ports implemented (port mask 0x2f)
ahci 0000:00:03.0: flags: 64bit ncq only

Suggested-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Niklas Cassel <cassel@kernel.org>