jtag: make debug arch defines local to jtag.c

Move debug arch defines to jtag.c since they aren't used anywhere else.
Also rename ARM_DEBUG_ARCH_V7_1 to ARM_DEBUG_ARCH_V7p1 to avoid clashes
with similar define in hw_breakpoint.h that is enabled when hardware
breakpoints are enabled.

Change-Id: I5f4b24b7aec50413f97a5b1854e6fadf2e4ab514
Signed-off-by: Pratik Patel <pratikp@codeaurora.org>