[AMDGPU] Fix GFX90A/GFX940 check prefix typos

Author: jayfoad

llvm/test/MC/AMDGPU/mai-gfx90a.s

@@ -28,7 +28,7 @@ v_accvgpr_mov_b32 a1, a2
 // GFX90A: v_accvgpr_mov_b32 a1, a2        ; encoding: [0x02,0xa5,0x02,0x7e]
 
 v_accvgpr_write_b32 a10, s20
-// GFX940: v_accvgpr_write_b32 a10, s20    ; encoding: [0x0a,0x40,0xd9,0xd3,0x14,0x00,0x00,0x18]
+// GFX90A: v_accvgpr_write_b32 a10, s20    ; encoding: [0x0a,0x40,0xd9,0xd3,0x14,0x00,0x00,0x18]
 
 v_mfma_f32_32x32x1f32 a[0:31], v0, v1, a[34:65]
 // GFX90A: v_mfma_f32_32x32x1f32 a[0:31], v0, v1, a[34:65] ; encoding: [0x00,0x80,0xc0,0xd3,0x00,0x03,0x8a,0x04]

llvm/test/MC/Disassembler/AMDGPU/gfx90a_mai.txt

@@ -21,7 +21,7 @@
 # GFX90A: v_accvgpr_mov_b32 a1, a2 ; encoding: [0x02,0xa5,0x02,0x7e]
 0x02,0xa5,0x02,0x7e
 
-# GFX940: v_accvgpr_write_b32 a10, s20 ; encoding: [0x0a,0x40,0xd9,0xd3,0x14,0x00,0x00,0x18]
+# GFX90A: v_accvgpr_write_b32 a10, s20 ; encoding: [0x0a,0x40,0xd9,0xd3,0x14,0x00,0x00,0x18]
 0x0a,0x40,0xd9,0xd3,0x14,0x00,0x00,0x18
 
 # GFX90A: v_mfma_f32_32x32x1f32 a[0:31], v0, v1, a[2:33] ; encoding: [0x00,0x80,0xc0,0xd3,0x00,0x03,0x0a,0x04]