Add pico2 arm flashless target board

Author: Felix "xq" Queißner

port/raspberrypi/rp2xxx/build.zig

@@ -17,6 +17,7 @@ boards: struct {
         pico: *const microzig.Target,
         pico_flashless: *const microzig.Target,
         pico2_arm: *const microzig.Target,
+        pico2_arm_flashless: *const microzig.Target,
         pico2_riscv: *const microzig.Target,
     },
     waveshare: struct {
@@ -191,6 +192,14 @@ pub fn init(dep: *std.Build.Dependency) Self {
                         .root_source_file = b.path("src/boards/raspberry_pi_pico2.zig"),
                     },
                 }),
+                .pico2_arm_flashless = chip_rp2350_arm.derive(.{
+                    .ram_image = true,
+                    .board = .{
+                        .name = "RaspberryPi Pico 2 (ram image)",
+                        .url = "https://www.raspberrypi.com/products/raspberry-pi-pico2/",
+                        .root_source_file = b.path("src/boards/raspberry_pi_pico2.zig"),
+                    },
+                }),
                 .pico2_riscv = chip_rp2350_riscv.derive(.{
                     .board = .{
                         .name = "RaspberryPi Pico 2",