libsel4bench: fix wrong PMU reg name

Current configuration never uses this reg because of a #ifndef,
but for some reason, clang still choose to compile the code containing
this reg causing compilation errors, whereas gcc would omit the code
and compile successfully.

libsel4bench/sel4_arch_include/aarch64/sel4bench/sel4_arch/sel4bench.h

diff --git a/libsel4bench/sel4_arch_include/aarch64/sel4bench/sel4_arch/sel4bench.h b/libsel4bench/sel4_arch_include/aarch64/sel4bench/sel4_arch/sel4bench.h
index 9275a75..b5d4f3b 100644
--- a/libsel4bench/sel4_arch_include/aarch64/sel4bench/sel4_arch/sel4bench.h
+++ b/libsel4bench/sel4_arch_include/aarch64/sel4bench/sel4_arch/sel4bench.h
@@ -23,7 +23,7 @@
 #define PMU_READ(reg, v) asm volatile("mrs %0, " reg :  "=r"(v))
 
 #define PMUSERENR   "PMUSERENR_EL0"
-#define PMINTENCLR  "PMINTENCLR_EL0"
+#define PMINTENCLR  "PMINTENCLR_EL1"
 #define PMINTENSET  "PMINTENSET_EL1"
 #define PMCR        "PMCR_EL0"
 #define PMCNTENCLR  "PMCNTENCLR_EL0"