build: use ninja for cmake packages by default

Speed goes from:

Executed in     178.08 secs     fish            external
usr time        20.16 mins      509.00 micros   20.16 mins
sys time        2.88 mins       39.00 micros    2.88 mins

To:

Executed in     175.90 secs     fish            external
usr time        20.19 mins      0.00 micros     20.19 mins
sys time        2.85 mins       497.00 micros   2.85 mins

Tested with "time make -j 12" on AMD Ryzen 3600

When building individual packages, the build time difference is often
significantly bigger than that.

Signed-off-by: Felix Fietkau <[email protected]>
Signed-off-by: Rosen Penev <[email protected]>

include/cmake.mk

@@ -1,5 +1,7 @@
 cmake_bool = $(patsubst %,-D%:BOOL=$(if $($(1)),ON,OFF),$(2))
 
+PKG_USE_NINJA ?= 1
+HOST_USE_NINJA ?= 1
 ifeq ($(PKG_USE_NINJA),1)
   PKG_BUILD_PARALLEL ?= 1
 endif