board/roseapplepi/genimage.cfg: beautify file

Beatify this genimage .cfg file to have consistency with all genimage .cfg
files in Buildroot.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

board/roseapplepi/genimage.cfg

@@ -3,13 +3,15 @@
 image boot.vfat {
 	vfat {
 		files = {
-		     "uEnv.txt",
-		     "uImage"
+			"uEnv.txt",
+			"uImage"
 		}
+
 		file kernel.dtb {
-		     image = "owl-s500-roseapplepi.dtb"
+			image = "owl-s500-roseapplepi.dtb"
 		}
 	}
+
 	size = 128M
 }
 
@@ -20,13 +22,13 @@ image sdcard.img {
 	partition s500-bootloader {
 		in-partition-table = "no"
 		image = "s500-bootloader.bin"
-		offset = 0x200200
+		offset = 0x200200 # 2MB + 512B
 	}
 
 	partition u-boot {
 		in-partition-table = "no"
 		image = "u-boot-dtb.img"
-		offset = 0x300000
+		offset = 3M
 	}
 
 	partition boot {