The maximum that you could from Solaris zone - to learn server family name via processor type.
For example, this is something from SPARC T7-* family:
user@zone:~$ psrinfo -vp
The physical processor has 6 virtual processors (16-21)
SPARC-M7 (chipid 0, clock 4133 MHz)
and you could only guess if it is primary or guest LDOM.
Also you could find some information about connected to LDOM disks via iostat:
user@zone:~$ iostat -En
ssd2 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: HITACHI Product: OPEN-V -SUN Revision: 8301 Serial No: 50413A37000E
Size: 214.75GB <214749020160 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 1343 Predictive Failure Analysis: 0 Non-Aligned Writes: 0
ssd3 Soft Errors: 0 Hard Errors: 6 Transport Errors: 6
Vendor: HITACHI Product: OPEN-V -SUN Revision: 8301 Serial No: 50413A37000D
Size: 483.18GB <483183820800 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 1343 Predictive Failure Analysis: 0 Non-Aligned Writes: 0
But there is no guarantee that this is full list of connected devices to physical server, because there may be several LDOMs on it.
PS/
If you have root access to LDOM, you may use virtinfo command to learn some parent machine information (you could not use it in zone):
root@ldom:~# virtinfo -a
Domain role: LDoms guest I/O
Domain name: domain1
Domain UUID: 8dff4050-8f62-4db5-b5b1-b14023fc058a
Control domain: physical-server-name.local
Chassis serial#: AK00000000
