Kernel: Improve the aarch64 kernel source files disk layout

Kernel/CMakeLists.txt

@@ -389,22 +389,35 @@ if (NOT "${SERENITY_ARCH}" STREQUAL "aarch64")
         ${CRYPTO_SOURCES}
     )
 else()
+    set(PREKERNEL_SOURCES
+        Arch/aarch64/Prekernel/PrekernelMMU.cpp
+        Arch/aarch64/Prekernel/PrekernelExceptions.cpp
+        Arch/aarch64/Prekernel/PrekernelCommon.cpp
+        Arch/aarch64/Prekernel/boot.S
+        Arch/aarch64/Prekernel/Aarch64_asm_utils.S
+
+        Prekernel/UBSanitizer.cpp
+    )
+    set(RPI_SOURCES
+        Arch/aarch64/RPi/GPIO.cpp
+        Arch/aarch64/RPi/Framebuffer.cpp
+        Arch/aarch64/RPi/Mailbox.cpp
+        Arch/aarch64/RPi/Timer.cpp
+        Arch/aarch64/RPi/UART.cpp
+        Arch/aarch64/RPi/MMIO.cpp
+    )
     set(SOURCES
         ${AK_SOURCES}
+        ${PREKERNEL_SOURCES}
+        ${RPI_SOURCES}
 
         Arch/aarch64/BootPPMParser.cpp
-        Arch/aarch64/CrashHandler.cpp
-        Arch/aarch64/GPIO.cpp
-        Arch/aarch64/Framebuffer.cpp
-        Arch/aarch64/Mailbox.cpp
-        Arch/aarch64/MainIdRegister.cpp
-        Arch/aarch64/MMIO.cpp
+        Arch/aarch64/CrashHandler.cpp        
+        Arch/aarch64/MainIdRegister.cpp        
         Arch/aarch64/PageDirectory.cpp
-        Arch/aarch64/Timer.cpp
-        Arch/aarch64/UART.cpp
         Arch/aarch64/Utils.cpp
 
-        Arch/aarch64/dummy.cpp
+        Arch/aarch64/Dummy.cpp
 
         # Preload specific
         Arch/aarch64/init.cpp
@@ -416,12 +429,10 @@ else()
         Arch/aarch64/boot.S
         Arch/aarch64/Aarch64_asm_utils.S
         Arch/aarch64/vector_table.S
-
         Arch/aarch64/SmapDisabler.cpp
         Arch/aarch64/ScopedCritical.cpp
-        MiniStdLib.cpp
-        Prekernel/UBSanitizer.cpp
 
+        MiniStdLib.cpp
         Heap/kmalloc.cpp
 
         Memory/AddressSpace.cpp