s390/disassembler: Update instruction mnemonics to latest spec

s390/disassembler: Update instruction mnemonics to latest spec

Over the course of CPU generations a few instructions got extended,
changing their base mnemonic, while keeping the former as an extended
mnemonic. Update the instruction mnemonics in the disassembler to their
latest base mnemonic as documented in the latest IBM z/Architecture
Principles of Operation specification [1].

With the IBM z14 the base mnemonics of the following vector instructions
have been changed:
- Vector FP Load Lengthened (VFLL)
- Vector FP Load Rounded (VFLR)

With Message-Security-Assist Extension 5 Perform Pseudorandom Number
Operation (PPNO) has been renamed to Perform Random Number Operation
(PRNO).

With Vector Enhancements Facility 2 the base mnemonics of the following
vector instructions have been changed:
- Vector FP Convert from Fixed (VCFPS)
- Vector FP Convert from Logical (VCFPL)
- Vector FP Convert to Fixed (VCSFP)
- Vector FP Convert to Logical (VCLFP)

[1] IBM z/Architecture Principles of Operation, SA22-7832-13, IBM z16,
    https://publibfp.dhe.ibm.com/epubs/pdf/a227832d.pdf

Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>