board/raspberrypi/config_4_64bit.txt: remove testing dtoverlay entries (vc4-kms-v3d-pi4, imx219)

Remove private/testing dtoverlay entries (vc4-kms-v3d-pi4, imx219 and
commented out ov5647) wrongly introduced by commit 689b9ac439
("package/rpi-firmware: rework boot/config file handling") [1].

[1] https://git.buildroot.net/buildroot/commit/?id=689b9ac439ab7b507c8982b6102bddf59d03efbf

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit fbf0a6ea427c7c1c837f79c74d591ec35eab3ba6)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

board/raspberrypi/config_4_64bit.txt

@@ -28,9 +28,5 @@ dtoverlay=miniuart-bt
 # enable autoprobing of Bluetooth driver without need of hciattach/btattach
 dtparam=krnbt=on
 
-dtoverlay=vc4-kms-v3d-pi4
-dtoverlay=imx219
-#dtoverlay=ov5647
-
 # enable 64bits support
 arm_64bit=1