Update rpi kernel recipe to handle upstream rpi3 b+ support

PKGBUILD

@@ -7,7 +7,7 @@ provides=("linux")
 # The firmware the kernel produces blows: don't falsify this lightly
 # "linux-firmware=20170309.695f2d6-1"
 pkgrel=1
-pkgver=4.17.rc0.r1.g734976ba80b7
+pkgver=4.18.rc2.r40.gcbe12ebc3410
 pkgdesc="Kernel build from head"
 arch=("x86_64" "aarch64")
 license=("GPL2.1")
@@ -49,8 +49,7 @@ package() {
     mkdir -p ${dtb_dir}
     cp arch/arm64/boot/Image ${boot_dir}
     cp ./arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dtb ${dtb_dir}
-    cp ./arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dtb ${dtb_dir}/bcm2837-rpi-3-b-plus.dtb
-    cp ./arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dtb ${dtb_dir}/bcm283x-rpi-other.dtb
+    cp ./arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b-plus.dtb ${dtb_dir}
   else
     cp arch/x86/boot/bzImage ${boot_dir}/vmlinuz-spudd