[M68k] Use M68010 cpu as target for SR move test (#122452)

Fixes the test introduced in #111145.

It would also make sense to throw an error when the user attempts to use
a move-from-sr on an unsupported architecture. Currently the encoder
generates garbage instructions for a 68000 because the AsmMatcher is
able to match the move against a MOV16rr

llvm/test/MC/M68k/Data/Classes/MxMoveSR.s

@@ -1,4 +1,4 @@
-; RUN: llvm-mc -triple=m68k -mcpu=M68000 -show-encoding %s | FileCheck %s
+; RUN: llvm-mc -triple=m68k -mcpu=M68010 -show-encoding %s | FileCheck %s
 
 ; CHECK:      move.w  %d1, %sr
 ; CHECK-SAME: encoding: [0x46,0xc1]