zasm: fix regression with lowercase (ix+d) parsing

apps/zasm/instr.asm

@@ -96,10 +96,12 @@ getInstID:
 parseIXY:
 	push	hl
 	ld	a, (hl)
+	call	upcase
 	cp	'I'
 	jr	nz, .end	; Z already unset
 	inc	hl
 	ld	a, (hl)
+	call	upcase
 	cp	'X'
 	jr	z, .match1
 	cp	'Y'

tools/tests/zasm/test1.asm

@@ -16,3 +16,4 @@ label2: .dw	0x42
 	ld	hl, bar
 	ld	ix, 1234
 	ld	iy, 2345
+	ld	(ix+1), l