mbed export -t uvision creates UV5 project files

[sg-]

Description

Creates *.uvoptx and *.uvprojx project files which are not compatible with Keil uVision 4.xx. If the exporter support is intended for UV4 the proper version of project files should be created. I couldn't find documentation about the version of IDE the export was supporting and given uvision and uvision5 are options I guessed there was support for UV4.

Target
All

mbed-cli version:
1.0.0

meed-os sha:
aa6d673 Merge pull request #3734 from ARMmbed/revert-3684-TARGET_STM_USB_CONFIG

[sarahmarshy]

We don't support UV4 anymore. Uvision is another alias UV5 right now.