Modify RAM size definition of ARMCC for GR-LYCHEE

[TomoYamanaka]

Description

I modified RAM size of ARMCC compiler for GR-LYCHEE.
In case of GR-LYCHEE, RAM size is 3M Byte(including Non-Cache area), but there was a typo at MACRO definition.

Pull request type

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

[0xc0170]

/morph build

[mbed-ci]

Build : SUCCESS

Build number : 2438
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/7311/

Triggering tests

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

[mbed-ci]

Exporter Build : SUCCESS

Build number : 2070
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/exporter/7311/

[mbed-ci]

Test : SUCCESS

Build number : 2218
Test logs :http://mbed-os-logs.s3-website-us-west-1.amazonaws.com/?prefix=logs/7311/2218