Suggestion: Consolidate C and C++ versions

[rei-vilo]

As for #1051 for tool-chains and utilities, each board package comes with different versions for C and C++.

On my laptop, retrieved from the platform.txt files:

Core	Version	C	C++
cc13x2	5.31.0-beta3	-std=c99	-std=c++98
cc13xx	4.9.1
cc3200	1.0.3	-std=gnu11	-std=gnu++11
cc3220emt	5.6.2
msp430	1.0.7
msp430elf	2.0.4
msp432	3.8.0
msp432e	5.19.0	-std=c99	-std=c++98
msp432p	5.29.0-beta1
msp432r	5.29.0
tivac	1.0.4	-std=gnu11	-std=gnu++11

Couldn't be nice to consolidate all those versions to ease maintenance and improve portability?