Sample lspci -vvxxxx output showing first 8 bytes of extended config space for
the L1 Substate Capability. Cannot show more since hardware is unreleased.

MJ: Added fake header, so that the test parses.

00:1c.0 PCI bridge:
        Capabilities: [200 v1] L1 PM Substates
                L1SubCap: PCI-PM_L1.2+, PCI-PM_L1.1+, ASPM_L1.2+, ASPM_L1.1+, L1_PM_Substates+
                          PortCommonModeRestoreTime=40us, PortTPowerOnTime=10us
00: 86 80 08 34 47 01 10 00 12 00 04 06 10 00 01 00
10: 00 00 00 00 00 00 00 00 00 01 01 00 10 10 00 00
20: 00 e0 90 e0 81 c7 f1 c7 00 00 00 00 00 00 00 00
30: 00 00 00 00 40 00 00 00 00 00 00 00 0b 01 00 00
40: 0d 60 00 00 86 80 53 4f 00 00 00 00 00 00 00 00
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
60: 05 90 02 01 20 00 00 00 00 00 00 00 00 00 00 00
70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: 10 e0 42 01 21 80 00 00 20 00 00 00 42 3c 39 01
a0: 42 00 41 70 1f 00 02 02 c0 07 48 01 00 00 01 00
b0: 00 00 00 00 3e 00 00 00 39 00 00 00 00 00 00 00
c0: 11 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 01 00 03 c8 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
100: 1e 00 01 00 1f 28 28 00