mem-cache: Delete squashed HWPrefetches
mem-cache: Delete squashed HWPrefetches

Request and Packet for squashed HWPrefetches were not deleted

Change-Id: I9b66bb01b8ed6a5ddfaaa8739a68165dc4a7006c
Signed-off-by: Pau Cabre <ef8132b29670afadf62d8ece2c6712b6f2bcc250@metempsy.com>
Reviewed-on: https://gem5-review.googlesource.com/4340
Maintainer: Nikos Nikoleris <b6a1b3cd9d36c44e9eeb16bc870df3cb2a0cf469@arm.com>
Reviewed-by: Nikos Nikoleris <b6a1b3cd9d36c44e9eeb16bc870df3cb2a0cf469@arm.com>

gem5/gem5,sobercoder/gem5,sobercoder/gem5,gem5/gem5,rallylee/gem5,rallylee/gem5,rallylee/gem5,sobercoder/gem5,rallylee/gem5,rallylee/gem5,TUD-OS/gem5-dtu,TUD-OS/gem5-dtu,TUD-OS/gem5-dtu,rallylee/gem5,gem5/gem5,rallylee/gem5,gem5/gem5,gem5/gem5,gem5/gem5,sobercoder/gem5,TUD-OS/gem5-dtu,sobercoder/gem5,gem5/gem5,sobercoder/gem5,TUD-OS/gem5-dtu,TUD-OS/gem5-dtu,sobercoder/gem5,TUD-OS/gem5-dtu