testing/firmware-qcom-adreno-extra: add missing replaces firmware-adreno (MR 2635)

This should fix upgrading from firmware-adreno to one of the subpackages
in case the new package is installed before firmware-adreno is uninstalled.

device/testing/firmware-qcom-adreno-extra/APKBUILD

 pkgname=firmware-qcom-adreno-extra
 pkgver=2
-pkgrel=0
+pkgrel=1
 pkgdesc="Extra Qualcomm Adreno GPU firmware from TheMuppets"
 url="https://github.com/TheMuppets/proprietary_vendor_sony"
 arch="armhf aarch64 armv7"
 license="proprietary"
 options="!check !archcheck !strip !spdx !tracedeps pmb:cross-native"
+replaces="firmware-adreno"
 
 # Sources
 _files1="a225_pm4.fw a225_pfp.fw a225p5_pm4.fw a330_pfp.fw a330_pm4.fw"