hw/arm/smmuv3: Correct SMMUEN field name in CR0

The FIELD macro for the SMMU enable bit in the CR0 register was
incorrectly named SMMU_ENABLE.

The ARM SMMUv3 Architecture Specification (both older IHI 0070.E.a and
newer IHI 0070.G.b) consistently refers to the SMMU enable bit as SMMUEN.

This change makes our implementation consistent with the manual.

Signed-off-by: Tao Tang <tangtao1634@phytium.com.cn>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Message-id: 20260304142344.3341444-3-tangtao1634@phytium.com.cn
Fixes: 10a83cb988 ("hw/arm/smmuv3: Skeleton")
Link: https://lists.nongnu.org/archive/html/qemu-arm/2025-09/msg01270.html
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/arm/smmuv3-internal.h

@@ -41,7 +41,7 @@ typedef enum SMMUTranslationClass {
 
 static inline int smmu_enabled(SMMUv3State *s)
 {
-    return FIELD_EX32(s->cr[0], CR0, SMMU_ENABLE);
+    return FIELD_EX32(s->cr[0], CR0, SMMUEN);
 }
 
 /* Command Queue Entry */

include/hw/arm/smmuv3-common.h

@@ -351,7 +351,7 @@ REG32(IDR5,                0x14)
 REG32(IIDR,                0x18)
 REG32(AIDR,                0x1c)
 REG32(CR0,                 0x20)
-    FIELD(CR0, SMMU_ENABLE,   0, 1)
+    FIELD(CR0, SMMUEN,   0, 1)
     FIELD(CR0, EVENTQEN,      2, 1)
     FIELD(CR0, CMDQEN,        3, 1)