target/ppc: Fix width of some 32-bit SPRs

target/ppc: Fix width of some 32-bit SPRs

Some 32-bit SPRs are incorrectly implemented as 64-bits on 64-bit
targets.

This changes VRSAVE, DSISR, HDSISR, DAWRX0, PIDR, LPIDR, DEXCR,
HDEXCR, CTRL, TSCR, MMCRH, and PMC[1-6] from to be 32-bit registers.

This only goes by the 32/64 classification in the architecture, it
does not try to implement finer details of SPR implementation (e.g.,
not all bits implemented as simple read/write storage).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Message-Id: <20230515092655.171206-2-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>