add comment, remove unused patch

overlay/libcamera.patch

@@ -1,19 +0,0 @@
-diff --git a/src/libcamera/source_paths.cpp b/src/libcamera/source_paths.cpp
-index 19689585..1380dfae 100644
---- a/src/libcamera/source_paths.cpp
-+++ b/src/libcamera/source_paths.cpp
-@@ -39,14 +39,6 @@ namespace {
-  */
- bool isLibcameraInstalled()
- {
--	/*
--	 * DT_RUNPATH (DT_RPATH when the linker uses old dtags) is removed on
--	 * install.
--	 */
--	for (const ElfW(Dyn) *dyn = _DYNAMIC; dyn->d_tag != DT_NULL; ++dyn) {
--		if (dyn->d_tag == DT_RUNPATH || dyn->d_tag == DT_RPATH)
--			return false;
--	}
- 
- 	return true;
- }

overlay/raspberrypi-wireless-firmware/5.10.87.nix

@@ -40,6 +40,11 @@ stdenvNoCC.mkDerivation {
     # CM4 symlink must be added since it's missing from upstream
     pushd $out/lib/firmware/brcm &>/dev/null
     ln -s "./brcmfmac43455-sdio.txt" "$out/lib/firmware/brcm/brcmfmac43455-sdio.raspberrypi,4-compute-module.txt"
+
+    # There are two options for the brcmfmac43455 binary: minimal or
+    # standard. For more info see the readme at:
+    # https://github.com/RPi-Distro/firmware-nonfree/blob/bullseye/debian/config/brcm80211/cypress/README.txt
+
     ln -sf ../cypress/cyfmac43455-sdio-minimal.bin brcmfmac43455-sdio.bin
     popd &>/dev/null