Tools, memap: Silence warnings that we handled correctly
Tools, memap: Silence warnings that we handled correctly

### Description

Memap will create a bunch of warnings about "Unknown object name" when
parsing a map file created for the RZ_A1H and the GR_Peach. Theses
warnings are sperious; the information in these sections does not belong
to an object file. This PR silences these warnings.

Fixes #6258

### Pull request type

    [x] Fix
    [ ] Refactor
    [ ] Target update
    [ ] Functionality change
    [ ] Breaking change

mbedmicro/mbed,kjbracey-arm/mbed,mbedmicro/mbed,mbedmicro/mbed,andcor02/mbed-os,andcor02/mbed-os,kjbracey-arm/mbed,mbedmicro/mbed,andcor02/mbed-os,mbedmicro/mbed,andcor02/mbed-os,kjbracey-arm/mbed,andcor02/mbed-os,andcor02/mbed-os,kjbracey-arm/mbed