temp/mesa: build freedreno for armv7 (!383)

Fix the regression from the mesa refactoring and from switching to armv7
in hammerhead.

[ci:skip-build]: already built successfully in CI for x86_64; I've
                 tested manually that it builds for armv7.

temp/mesa/APKBUILD

@@ -5,7 +5,7 @@
 pkgname=mesa
 pkgver=9999
 _pkgver=19.1.0-rc1
-pkgrel=4
+pkgrel=5
 pkgdesc="[${_pkgver}] Mesa DRI OpenGL library"
 url="https://www.mesa3d.org"
 arch="armhf armv7 aarch64"
@@ -77,7 +77,7 @@ x86*)
 			$pkgname-dri-intel:_dri \
 			$pkgname-dri-vmwgfx:_dri"
 	;;
-armhf|aarch64)
+armhf|armv7|aarch64)
 	_gallium_drivers="${_gallium_drivers},kmsro,vc4,freedreno,panfrost,etnaviv,tegra,lima"
 	_vulkan_drivers="${_vulkan_drivers}"
 	subpackages="$subpackages