Update to android-mainline kernel headers v5.4.

Update generate_uapi_headers.sh to checkout the android mainline
kernel. Also, add a small modification to look for the kernel directory
in common not linux-stable.

Remove deprecated android headers from android/uapi/linux. Also,
remove f_accessory.h since it's in the android mainline kernel.

Test: Builds and runs on walleye.
Change-Id: Ia371305e19f56e6bcc2db6d5b4d299819f07ffc6
diff --git a/libc/kernel/uapi/drm/drm_mode.h b/libc/kernel/uapi/drm/drm_mode.h
index 403c787..be5cbad 100644
--- a/libc/kernel/uapi/drm/drm_mode.h
+++ b/libc/kernel/uapi/drm/drm_mode.h
@@ -73,7 +73,12 @@
 #define DRM_MODE_FLAG_PIC_AR_16_9 (DRM_MODE_PICTURE_ASPECT_16_9 << 19)
 #define DRM_MODE_FLAG_PIC_AR_64_27 (DRM_MODE_PICTURE_ASPECT_64_27 << 19)
 #define DRM_MODE_FLAG_PIC_AR_256_135 (DRM_MODE_PICTURE_ASPECT_256_135 << 19)
-#define DRM_MODE_FLAG_ALL (DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_PVSYNC | DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_INTERLACE | DRM_MODE_FLAG_DBLSCAN | DRM_MODE_FLAG_CSYNC | DRM_MODE_FLAG_PCSYNC | DRM_MODE_FLAG_NCSYNC | DRM_MODE_FLAG_HSKEW | DRM_MODE_FLAG_DBLCLK | DRM_MODE_FLAG_CLKDIV2 | DRM_MODE_FLAG_3D_MASK)
+#define DRM_MODE_FLAG_SUPPORTS_RGB (1 << 27)
+#define DRM_MODE_FLAG_SUPPORTS_YUV (1 << 28)
+#define DRM_MODE_FLAG_VID_MODE_PANEL (1 << 29)
+#define DRM_MODE_FLAG_CMD_MODE_PANEL (1 << 30)
+#define DRM_MODE_FLAG_SEAMLESS (1 << 31)
+#define DRM_MODE_FLAG_ALL (DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_PVSYNC | DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_INTERLACE | DRM_MODE_FLAG_DBLSCAN | DRM_MODE_FLAG_CSYNC | DRM_MODE_FLAG_PCSYNC | DRM_MODE_FLAG_NCSYNC | DRM_MODE_FLAG_HSKEW | DRM_MODE_FLAG_DBLCLK | DRM_MODE_FLAG_CLKDIV2 | DRM_MODE_FLAG_SUPPORTS_RGB | DRM_MODE_FLAG_SUPPORTS_YUV | DRM_MODE_FLAG_VID_MODE_PANEL | DRM_MODE_FLAG_CMD_MODE_PANEL | DRM_MODE_FLAG_3D_MASK)
 #define DRM_MODE_DPMS_ON 0
 #define DRM_MODE_DPMS_STANDBY 1
 #define DRM_MODE_DPMS_SUSPEND 2
@@ -217,6 +222,7 @@
 #define DRM_MODE_CONNECTOR_DSI 16
 #define DRM_MODE_CONNECTOR_DPI 17
 #define DRM_MODE_CONNECTOR_WRITEBACK 18
+#define DRM_MODE_CONNECTOR_SPI 19
 struct drm_mode_get_connector {
   __u64 encoders_ptr;
   __u64 modes_ptr;
@@ -303,6 +309,7 @@
 };
 #define DRM_MODE_FB_INTERLACED (1 << 0)
 #define DRM_MODE_FB_MODIFIERS (1 << 1)
+#define DRM_MODE_FB_SECURE (1 << 2)
 struct drm_mode_fb_cmd2 {
   __u32 fb_id;
   __u32 width;