Allow bigger increments in ezflash tester

source/prog/ezflash_test.asm

@@ -126,8 +126,14 @@ main:
     jr main
 
 .joy_up
-    ld de, $10
     ldh a, [h_joypad_down]
+    ld de, $1000
+    bit joy_select_f, a
+    jr nz, .joy_up_done
+    ld de, $100
+    bit joy_start_f, a
+    jr nz, .joy_up_done
+    ld de, $10
     bit joy_b_f, a
     jr nz, .joy_up_done
     ld de, 1
@@ -136,14 +142,20 @@ main:
     jr main
 
 .joy_down
-    ld de, -$10
     ldh a, [h_joypad_down]
+    ld de, -$1000
+    bit joy_select_f, a
+    jr nz, .joy_down_done
+    ld de, -$100
+    bit joy_start_f, a
+    jr nz, .joy_down_done
+    ld de, -$10
     bit joy_b_f, a
     jr nz, .joy_down_done
     ld de, -1
 .joy_down_done
     call update_val
-    jr main
+    jp main
 
 update_val:
 ; de: value increment