arch-arm: Use uint64_t for AArch64 MiscReg operands
arch-arm: Use uint64_t for AArch64 MiscReg operands

At the moment those operands are using uint32_t (uw) variables,
therefore losing the content of the 32 most significant bits

This is not a problem for some of them (like CPTR_EL2, CPTR_EL3)
as [63:32] bits are RES0 for now.
HCR_EL2 on the other hand holds meaningful bits in [63:32],
HCR_EL.E2H being a notable example. With this patch we
are then fixing a bug in VHE (which relies on E2H)

Change-Id: I3e31009ad3dec8d8ea1c1057a189f7dcc2c3a54c
Signed-off-by: Giacomo Travaglini <8eef13a4f970e2e9372c8d26ad0737b760f99c02@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/58113
Reviewed-by: Andreas Sandberg <c9f5686ee5bd561c93f9de79681eee75bfa7f36e@arm.com>
Maintainer: Andreas Sandberg <c9f5686ee5bd561c93f9de79681eee75bfa7f36e@arm.com>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

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