brcmfmac_sdio-firmware-rpi: add patch to sync with rasbian buster

The boardflags3 change in brcmfmac43455-sdio.txt is needed to get
bluetooth working on RPi4.

Replace this patch with a PKG_VERSION bump once the brcmfmac43455-sdio.txt
file is publically available.

Signed-off-by: Matthias Reichl <hias@horus.com>

packages/linux-firmware/brcmfmac_sdio-firmware-rpi/patches/brcmfmac_sdio-firmware-rpi-001-sync-with-raspbian-buster.patch

@@ -0,0 +1,21 @@
+diff -ru brcmfmac_sdio-firmware-rpi.orig/firmware/brcm/brcmfmac43455-sdio.txt brcmfmac_sdio-firmware-rpi/firmware/brcm/brcmfmac43455-sdio.txt
+--- brcmfmac_sdio-firmware-rpi.orig/firmware/brcm/brcmfmac43455-sdio.txt	2019-01-28 20:44:58.000000000 +0100
++++ brcmfmac_sdio-firmware-rpi/firmware/brcm/brcmfmac43455-sdio.txt	2019-06-11 13:09:30.388579306 +0200
+@@ -21,7 +21,7 @@
+ #            bit1 for btcoex
+ boardflags=0x00480201
+ boardflags2=0x40800000
+-boardflags3=0x48200100
++boardflags3=0x44200100
+ phycal_tempdelta=15
+ rxchain=1
+ txchain=1
+@@ -91,7 +91,7 @@
+ cbfilttype=1
+ fdsslevel_ch11=6
+ 
+-# Experimental Bluetooth coexistence parameters from Cypress
++# Improved Bluetooth coexistence parameters from Cypress
+ btc_mode=1
+ btc_params8=0x4e20
+ btc_params1=0x7530