Update to v5.5 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-5.5

Test: Boots on walleye.
Test: Ran bionic-unit-tests on walleye.
Test: Boots on cuttlefish.
Test: Ran bionic-unit-tests on cuttlefish.
Change-Id: I57387d3c31e0ba5ad125ffe291cecf365c7b374e
Merged-In: I57387d3c31e0ba5ad125ffe291cecf365c7b374e
diff --git a/libc/kernel/uapi/drm/amdgpu_drm.h b/libc/kernel/uapi/drm/amdgpu_drm.h
index 1d95379..b986d30 100644
--- a/libc/kernel/uapi/drm/amdgpu_drm.h
+++ b/libc/kernel/uapi/drm/amdgpu_drm.h
@@ -301,6 +301,7 @@
 #define AMDGPU_VM_MTYPE_WC (2 << 5)
 #define AMDGPU_VM_MTYPE_CC (3 << 5)
 #define AMDGPU_VM_MTYPE_UC (4 << 5)
+#define AMDGPU_VM_MTYPE_RW (5 << 5)
 struct drm_amdgpu_gem_va {
   __u32 handle;
   __u32 _pad;