arch-arm: Correct the Ids and names of the PMU events
arch-arm: Correct the Ids and names of the PMU events

0x0C is the PC_WRITE_RETIRED event and 0x21 is the RetiredBranches.

Change-Id: I5f1173ff06f67b6a46e8a914c8acb9639edf67ec
Signed-off-by: Andriani Mappoura <0b4d5adb990b9cd788b319cd3ba64622294f120a@arm.com>
Reviewed-by: Nikos Nikoleris <b6a1b3cd9d36c44e9eeb16bc870df3cb2a0cf469@arm.com>
Reviewed-by: Giacomo Travaglini <8eef13a4f970e2e9372c8d26ad0737b760f99c02@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26485
Maintainer: Giacomo Travaglini <8eef13a4f970e2e9372c8d26ad0737b760f99c02@arm.com>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5