Fix ARMv8.1/v8.2 for hw watchpoint and breakpoint

Fix ARMv8.1/v8.2 for hw watchpoint and breakpoint

The problem here is ARMv8.1 (and ARMv8.2) define a
different debug version than ARMv8 (7 and 8 respectively).
This fixes hw watchpoints and breakpoints by checking
for those debug versions too.

Committed as obvious after a test on aarch64-linux-gnu
(on a ThunderX machine which has ARMv8.1 support enabled).

ChangeLog:
	* nat/aarch64-linux-hw-point.c
	(aarch64_linux_get_debug_reg_capacity): Handle
	ARMv8.1 and ARMv8.2 debug versions.
	* nat/aarch64-linux-hw-point.h
	(AARCH64_DEBUG_ARCH_V8_1): New define.
	(AARCH64_DEBUG_ARCH_V8_2): New define.

Signed-off-by: Andrew Pinski <apinski@cavium.com>