Common: Set bFMA to true for AArch64

Without this, the code added in ac28b89 misbehaves and considers
AArch64 netplay clients to not have hardware FMA support, telling
all clients to disable FMA support, which causes a desync between
x64 and AArch64 due to JitArm64 not being able to disable FMA support.

Source/Core/Common/ArmCPUDetect.cpp

@@ -68,6 +68,7 @@ void CPUInfo::Detect()
   CPU64bit = true;
   Mode64bit = true;
   vendor = CPUVendor::ARM;
+  bFMA = true;
   bFlushToZero = true;
   bAFP = false;