fairphone-fp4: set sector size to 4096 (MR 3036)

Now that internal storage is supported, we actually need a 4096 sector
size, otherwise kpartx won't work on internal partitions.

[ci:skip-build] Already built successfuly on CI in MR

device/testing/device-fairphone-fp4/APKBUILD

@@ -2,7 +2,7 @@
 pkgname=device-fairphone-fp4
 pkgdesc="Fairphone 4"
 pkgver=0.4
-pkgrel=0
+pkgrel=1
 url="https://postmarketos.org"
 license="MIT"
 arch="aarch64"
@@ -60,7 +60,7 @@ phosh() {
 }
 
 sha512sums="
-5437e5d3b6fe8041fe16575c47ad5147f62108e68873fbed6f4f7ce3507e3c3bef533ef14194892280bb763461a09b9eac41caa3b5c4cdb8140c40ef5af2e8b7  deviceinfo
+d84e25eda52b40a0ca3bcfed79d4f73bfc7b28889d1882a5b78dffe069fdeb54390f0dea800e4ae4aae2011322b410551c204caf4a39fdf42d5faf3869f95556  deviceinfo
 25a93dcbe6dbc6cff24f57cbf5539bc475c5fe0f6bf5e8374c7032b9c38a939bef0aa0cde1707afcc16b1ec2d0859c03c6ee92d80d8048d1c6adc6e25178b85f  gtk.css
 9fef488a655fcbad4fb28c11d7d6cbe385096e766cd99ca59802f1dbc4e3c99dac0ff682549e02fac0b73f7e95db953f3a87c453d1b19b229785e4ffeec515ed  rootston.ini
 "

device/testing/device-fairphone-fp4/deviceinfo

@@ -34,3 +34,4 @@ deviceinfo_flash_offset_kernel="0x00008000"
 deviceinfo_flash_offset_ramdisk="0x01000000"
 deviceinfo_flash_offset_second="0x00000000"
 deviceinfo_flash_offset_tags="0x00000100"
+deviceinfo_rootfs_image_sector_size="4096"