RISC-V: Replace hardcoded constants with enum values

The RISC-V device-tree code has a number of hard-coded
constants and this change moves them into header enums.

Cc: Sagar Karandikar <sagark@eecs.berkeley.edu>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

include/hw/riscv/sifive_clint.h

@@ -47,4 +47,8 @@ enum {
     SIFIVE_TIME_BASE    = 0xBFF8
 };
 
+enum {
+    SIFIVE_CLINT_TIMEBASE_FREQ = 10000000
+};
+
 #endif

include/hw/riscv/sifive_u.h

@@ -50,6 +50,10 @@ enum {
     SIFIVE_U_UART1_IRQ = 4
 };
 
+enum {
+    SIFIVE_U_CLOCK_FREQ = 1000000000
+};
+
 #define SIFIVE_U_PLIC_HART_CONFIG "MS"
 #define SIFIVE_U_PLIC_NUM_SOURCES 127
 #define SIFIVE_U_PLIC_NUM_PRIORITIES 7

include/hw/riscv/spike.h

@@ -42,6 +42,10 @@ enum {
     SPIKE_DRAM
 };
 
+enum {
+    SPIKE_CLOCK_FREQ = 1000000000
+};
+
 #if defined(TARGET_RISCV32)
 #define SPIKE_V1_09_1_CPU TYPE_RISCV_CPU_RV32GCSU_V1_09_1
 #define SPIKE_V1_10_0_CPU TYPE_RISCV_CPU_RV32GCSU_V1_10_0

include/hw/riscv/virt.h

@@ -55,6 +55,10 @@ enum {
     VIRTIO_NDEV = 10
 };
 
+enum {
+    VIRT_CLOCK_FREQ = 1000000000
+};
+
 #define VIRT_PLIC_HART_CONFIG "MS"
 #define VIRT_PLIC_NUM_SOURCES 127
 #define VIRT_PLIC_NUM_PRIORITIES 7