CMake: Use full LTO

Speeds up Vulkan backend a bit compared to LTO_PCSX2_CORE, since Vulkan calls into a lot of common methods

.github/workflows/linux_build_matrix.yml

@@ -15,7 +15,7 @@ jobs:
     with:
       jobName: "with LTO"
       compiler: gcc
-      cmakeflags: "-DLTO_PCSX2_CORE=ON"
+      cmakeflags: "-DCMAKE_INTERPROCEDURAL_OPTIMIZATION=ON"
       buildAppImage: true
     secrets: inherit
 

.github/workflows/macos_build.yml

@@ -91,7 +91,7 @@ jobs:
       - name: Generate CMake Files
         run: |
           QT_BUILD=$([ "${{ inputs.gui }}" == "Qt" ] && echo "ON" || echo "OFF")
-          cmake -DCMAKE_PREFIX_PATH="$HOME/deps" -DCMAKE_BUILD_TYPE=Release -DQT_BUILD="$QT_BUILD" -DUSE_OPENGL=OFF -DDISABLE_ADVANCE_SIMD=ON -DLTO_PCSX2_CORE=ON -DUSE_SYSTEM_LIBS=OFF -DUSE_SYSTEM_SDL2=ON -B build .
+          cmake -DCMAKE_PREFIX_PATH="$HOME/deps" -DCMAKE_BUILD_TYPE=Release -DQT_BUILD="$QT_BUILD" -DUSE_OPENGL=OFF -DDISABLE_ADVANCE_SIMD=ON -DCMAKE_INTERPROCEDURAL_OPTIMIZATION=ON -DUSE_SYSTEM_LIBS=OFF -DUSE_SYSTEM_SDL2=ON -B build .
 
       - name: Build PCSX2
         working-directory: build

.github/workflows/windows_build_wx.yml

@@ -78,7 +78,7 @@ jobs:
           if "${{ inputs.platform }}"=="Win32" (SET vcvars=vcvarsamd64_x86.bat) else (SET vcvars=vcvars64.bat)
           call "%ProgramFiles(x86)%\Microsoft Visual Studio\2019\Enterprise\VC\Auxiliary\Build\%vcvars%"
           echo ::set-output name=vcvars::%vcvars%
-          cmake . -B build -DCMAKE_BUILD_TYPE=Release -DLTO_PCSX2_CORE=ON -G Ninja
+          cmake . -B build -DCMAKE_BUILD_TYPE=Release -DCMAKE_INTERPROCEDURAL_OPTIMIZATION=ON -G Ninja
 
       - name: Build PCSX2
         shell: cmd