This patch cleans up old tools/power/acpi Makefile for further porting,
make it compiled in a similar way as the other tools.  No functional
changes.

The CFLAGS is modified as follows:
1. Previous cc flags:
   -Wall -Wstrict-prototypes -Wdeclaration-after-statement -Os -s \
   -D_LINUX -DDEFINE_ALTERNATE_TYPES -I../../../include
2. Current cc flags:
   DEBUG=false:
   -D_LINUX -DDEFINE_ALTERNATE_TYPES -I../../../include -Wall \
   -Wstrict-prototypes -Wdeclaration-after-statement -Os \
   -fomit-frame-pointer
   Normal:
   -D_LINUX -DDEFINE_ALTERNATE_TYPES -I../../../include -Wall \
   -Wstrict-prototypes -Wdeclaration-after-statement -O1 -g -DDEBUG

There is only one difference: -fomit-frame-pointer.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>