Ensure reliable VFAT external reset from LpGBT on ME0

Description

While testing the VFAT external reset from the LpGBT on ME0, two issues were noticed:

1. The addition of the RC circuit on the ME0 VFAT3 plugin card reset line calls for an extended reset pulse duration. Following the chip designers' recommendations, it must be at least ~25 ms.
2. The gem::hardware::lpgbt::resetVFAT function could return corrupted values, leading to uncertainties in understanding on which VFAT the external reset was successfully attempted.

This merge request fixes both issues.

Related Issue

How Has This Been Tested?

Tested thoroughly on the QC7 and QC8 stands.

Types of changes

• 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.

gemhardware/src/blaster.cpp

@@ -165,7 +165,7 @@ uint32_t gem::hardware::blaster::execute::operator()(const uint32_t optohybridMa
     // Manually reset all VFAT
     for (size_t ohN = 0; ohN < amc::number_oh(); ++ohN)
         /* ignored = */ lpgbt::resetVFAT(ohN, oh::FULL_VFAT_MASK);
-    std::this_thread::sleep_for(std::chrono::milliseconds(25)); // Ensure VFAT are out of reset
+    std::this_thread::sleep_for(std::chrono::milliseconds(50)); // Ensure VFAT are out of reset
 #endif
 
     // Issue a link reset to clear the GBT status registers