use <sys/prctl.h> to enhance portability (clang)

using <sys/prctl.h> and <linux/prctl.h> simultaneously causes clang to
fail:

```
In file included from FEX/FEXCore/Source/Utils/AllocatorHooks.cpp:6:
/usr/include/sys/prctl.h:88:8: error: redefinition of 'prctl_mm_map'
   88 | struct prctl_mm_map {
      |        ^
/usr/include/linux/prctl.h:134:8: note: previous definition is here
  134 | struct prctl_mm_map {
      |        ^
1 error generated.
```

prefer <sys/prctl.h> and do not include <linux/prctl.h>

fix: #5454
Signed-off-by: Pepper Gray <hello@peppergray.xyz>

FEXCore/Source/Interface/Core/CPUBackend.cpp

@@ -12,7 +12,6 @@
 #include <cstdint>
 
 #ifndef _WIN32
-#include <linux/prctl.h>
 #include <sys/prctl.h>
 #endif
 

FEXCore/Source/Utils/AllocatorHooks.cpp

@@ -2,7 +2,6 @@
 #ifdef ENABLE_FEX_ALLOCATOR
 #include <rpmalloc/rpmalloc.h>
 #ifndef _WIN32
-#include <linux/prctl.h>
 #include <sys/prctl.h>
 #include <sys/mman.h>
 #else

FEXCore/include/FEXCore/Utils/PrctlUtils.h

@@ -2,7 +2,6 @@
 #pragma once
 
 #ifndef _WIN32
-#include <linux/prctl.h>
 #include <sys/mman.h>
 #include <sys/user.h>
 #include <sys/prctl.h>

Source/Tools/FEXInterpreter/ELFCodeLoader.h

@@ -32,7 +32,6 @@
 #include <sys/personality.h>
 #include <sys/prctl.h>
 #include <sys/random.h>
-#include <linux/prctl.h>
 
 #define PAGE_START(x) ((x) & ~(uintptr_t)(4095))
 #define PAGE_OFFSET(x) ((x) & 4095)