nvmem: layouts: onie-tlv: fix hang on unknown types

In the Linux kernel, the following vulnerability has been resolved:

nvmem: layouts: onie-tlv: fix hang on unknown types

The EEPROM on my board has a vendor specific entry of type 0x41. When

stumbling upon that, this driver hangs in an endless loop.

Fix it by keep incrementing the offset on unknown entries, so the loop

will eventually stop.