ls-ecaps: Add decode support for IDE Extended Capability

ls-ecaps: Add decode support for IDE Extended Capability

IDE (Integrity & Data Encryption) Extended Capability defined in [1]
implements control of the PCI link encryption. The verbose level > 2 prints
offsets of the fields to make running setpci easier.

The example output is:

Capabilities: [830 v1] Integrity & Data Encryption
	IDECap: Lnk=0 Sel=1 FlowThru- PartHdr- Aggr- PCPC- IDE_KM+ Alg='AES-GCM-256-96b' TCs=8 TeeLim+
	IDECtl: FTEn-
	SelectiveIDE#0 Cap: RID#=1
	SelectiveIDE#0 Ctl: En- NPR- PR- CPL- PCRC- HdrEnc=no Alg='AES-GCM-256-96b' TC0 ID0
	SelectiveIDE#0 Sta: insecure RecvChkFail-
	SelectiveIDE#0 RID: Valid- Base=0 Limit=0 SegBase=0
	SelectiveIDE#0 RID#0: Valid- Base=0 Limit=0

[1] PCIe r6.0.1, sections 6.33, 7.9.26

Signed-off-by: Alexey Kardashevskiy <aik@amd.com>