FPGAIO: Add MISC IO initialization support

[shuoo]

Description

Enable MISC FPGA IO support on CM3DS, it will be needed by several peripherals. We are going to enable SPI SD card in the future, and SPI_nSS pin is requied.

Tested locally with CM3DS on MPS2+.

Pull request type

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

[0xc0170]

/morph build

[mbed-ci]

Build : SUCCESS

Build number : 2185
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/7039/

Triggering tests

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

[mbed-ci]

Test : SUCCESS

Build number : 1974
Test logs :http://mbed-os-logs.s3-website-us-west-1.amazonaws.com/?prefix=logs/7039/1974

[cmonr]

/morph mbed2-build

[mbed-ci]

Exporter Build : FAILURE

Build number : 1813
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/exporter/7039/

[0xc0170]

/morph export-build

[mbed-ci]

Exporter Build : SUCCESS

Build number : 1819
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/exporter/7039/