target/arm: Correct definition of PMCRDP

The PMCR_EL0.DP bit is bit 5, which is 0x20, not 0x10.  0x10 is 'X'.
Correct our #define of PMCRDP and add the missing PMCRX.

We do have the correct behaviour for handling the DP bit being
set, so this fixes a guest-visible bug.

Fixes: 033614c4Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 20200214175116.9164-17-peter.maydell@linaro.org

target/arm/helper.c

@@ -1017,7 +1017,8 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
 #define PMCRN_MASK  0xf800
 #define PMCRN_SHIFT 11
 #define PMCRLC  0x40
-#define PMCRDP  0x10
+#define PMCRDP  0x20
+#define PMCRX   0x10
 #define PMCRD   0x8
 #define PMCRC   0x4
 #define PMCRP   0x2