Use python from toolchain instead of local copy

Previous commit used /usr/bin/python to parse a yaml file and that
resulted in CI failures and this patch corrects that by using the
one in toolchain.

Change-Id: I0f3efcab0c0f620a6ddb7b3500aca5694351fe10
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>
diff --git a/Makefile.am b/Makefile.am
index 1557aad..04dab40 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -10,9 +10,8 @@
 BUILT_SOURCES = led-gen.hpp
 CLEANFILES = led-gen.hpp
 
-PYTHON="/usr/bin/python"
 led-gen.hpp: ${srcdir}/parse_led.py
-	${AM_V_at}${PYTHON} $^ > $@
+	$(PYTHON) $^ > $@
 
 phosphor_ledmanager_LDFLAGS = $(SYSTEMD_LIBS)
 phosphor_ledmanager_CFLAGS = $(SYSTEMD_CFLAGS)