Fix support for SRAM

[martin-kuhn]

Description

This fixes an issue if someone wants to use FSMC with a external SRAM.

Motivation and Context

An external memory like a NOR Flash or PSRAM can be connected using the onboard FSMC and the SRAM driver provided by the nf-overlay. The actual code in targets/CMSIS-OS/ChibiOS/nanoCLR/targetHAL_Power.c does only support SDRAM. If someone uses the SRAM driver instead of the SDRAM driver, this causes an error.

How Has This Been Tested?

I am using an external PSRAM on my board which is connected with the SRAMD2 driver, which works fine with the above fix.

Types of changes

• Improvement (non-breaking change that improves a feature, code or algorithm)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[nfbot]

Hi @martin-kuhn,

I'm nanoFramework bot.
Thank you for your contribution!

A human will be reviewing it shortly. 😉

[CLAassistant]

All committers have signed the CLA.

[josesimoes]

LGTM! thanks for providing this fix. 👍