kgdb,ppc: Fix regression in evr register handling

Commit ff10b88b (kgdb,ppc: Individual
register get/set for ppc) introduced a problem where memcpy was used
incorrectly to read and write the evr registers with a kernel that
has:

CONFIG_FSL_BOOKE=y
CONFIG_SPE=y
CONFIG_KGDB=y

This patch also fixes the following compilation problems:

arch/powerpc/kernel/kgdb.c: In function 'dbg_get_reg':
arch/powerpc/kernel/kgdb.c:341: error: passing argument 2 of 'memcpy' makes pointer from integer without a cast
arch/powerpc/kernel/kgdb.c: In function 'dbg_set_reg':
arch/powerpc/kernel/kgdb.c:366: error: passing argument 1 of 'memcpy' makes pointer from integer without a cast

[jason.wessel@windriver.com: Remove void * casts and fix patch header]
Reported-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
CC: linuxppc-dev@lists.ozlabs.org