Disabled STM ethernet driver hardware checksum calculation

[mikaleppanen]

Description

No need for driver level hardware IPv4/TCP/UDP/ICMP checksum insertion
since LWIP and nanostack handles those already.

Related to issue: #7227

Pull request type

[X] Fix
[ ] Refactor
[ ] New target
[ ] Feature
[ ] Breaking change

[0xc0170]

/morph build

[mbed-ci]

Build : SUCCESS

Build number : 2367
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/7229/

Triggering tests

/morph test
/morph uvisor-test
/morph export-build
/morph mbed2-build

[mbed-ci]

Exporter Build : SUCCESS

Build number : 2000
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/exporter/7229/

[mbed-ci]

Test : SUCCESS

Build number : 2156
Test logs :http://mbed-os-logs.s3-website-us-west-1.amazonaws.com/?prefix=logs/7229/2156

[cmonr]

/morph uvisor-test