temp/u-boot-pinephone: refactor $freq logic (MR 2155)

* Prevent interactive warning to pop once already approved when
  [over/down]clocking DRAM
* Make sure $freq is always set

Co-Authored-By: Oliver Smith <ollieparanoid@postmarketos.org>

temp/u-boot-pinephone/APKBUILD

@@ -46,6 +46,8 @@ package() {
 	install -D -m 755 "$srcdir"/update-u-boot "$pkgdir"/usr/sbin/update-u-boot
 }
 
-sha512sums="73b132cdc26113a83d060f0d243320ca989b4efa98fe95a2205526a42f615ced7046bb9d4878c67a9a550b04c2519d90be3c2272be97c878d759bf5d027cf536  u-boot-7492749fec31b1086bc8933bf113a766aea021aa.tar.gz
+sha512sums="
+73b132cdc26113a83d060f0d243320ca989b4efa98fe95a2205526a42f615ced7046bb9d4878c67a9a550b04c2519d90be3c2272be97c878d759bf5d027cf536  u-boot-7492749fec31b1086bc8933bf113a766aea021aa.tar.gz
 3cba8a0e899be8cb0b9260b7a86d4115f74c279a1bac8c1403ee669adf91dca8215d8d2d6395ebb3cd67ce000f37a51d6e033b62a8d616b346a9072fa58a4b70  0001-expose-DRAM-clock-speed.patch
-f460cb51737df2ba9ca94522338a8d651c68492a102f2d02098161afa02262537a19f5e9c03b47f86cbbc75d77fda1e19fa848a2b03dd4429abb827d2645b549  update-u-boot"
+d6b80f900453f40bd0f133e4beee31039a4088cdaa6e68b224c7c3d905b12e125f74d69d18b492ecae24a793e15abead8246d2118091f58761d2e0b54251586d  update-u-boot
+"

temp/u-boot-pinephone/update-u-boot

@@ -38,8 +38,14 @@ get_defaults() {
 	fi
 
 	if [ -z "$freq" -a -e /proc/device-tree/memory/ram_freq ]; then
-		freq=$(cat /proc/device-tree/memory/ram_freq 2>/dev/null)
-		echo Detected custom clock: $freq MHz
+		proc_freq=$(cat /proc/device-tree/memory/ram_freq 2>/dev/null)
+		if [ -n "$proc_freq" ]; then
+			echo "Detected clock: $proc_freq MHz"
+			default_freq="$proc_freq"
+		else
+			echo "WARNING: Failed to read clock from /proc/device-tree/memory/ram_freq"
+			echo "Using default clock: $default_freq MHz"
+		fi
 	elif [ -z "$freq" ]; then
 		echo Using default clock: $default_freq MHz
 	else
@@ -145,13 +151,15 @@ if [ -z "$dryrun" ]; then
 		then
 			exit 0
 		fi
-	else
-		freq=$default_freq
 	fi
 	echo "Updating $board u-boot in $device in 3 seconds..."
 	sleep 3
 fi
 
+if [ -z "$freq" ]; then
+	freq=$default_freq
+fi
+
 (
 set -e
 case "$board" in