target/armv4_5: fix register numbering overlap

Commit b5d2b1224f ("target/cortex_a: add hypervisor mode")
added sp_hyp, spsr_hyp registers with gdb_index 51 and 52
but did not moved FP regs enum base starting from 51.

Move FP registers indices to make room for added registers.

Change-Id: I4338777545918fdf62016e06764308dacea61e98
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/9235
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/target/arm.h

@@ -108,7 +108,8 @@ enum arm_mode {
 
 /* VFPv3 internal register numbers mapping to d0:31 */
 enum {
-	ARM_VFP_V3_D0 = 51,
+	ARM_VFP_V3_D0 = 53,
+	// numbering should not overlap with e.g. armv4_5.c arm_core_regs .gdb_index
 	ARM_VFP_V3_D1,
 	ARM_VFP_V3_D2,
 	ARM_VFP_V3_D3,