Conditionally change CFLAGS/LDFLAGS in two places

Makefile

@@ -89,6 +89,14 @@ pkgconfigdir ?= $(libdir)/pkgconfig
 CFLAGS  += -I$(INC_PATH) -I$(SRC_PATH) -I$(SRC_PATH)/wrappers/themis/
 LDFLAGS += -L$(BIN_PATH)
 
+ifneq ($(ENGINE),boringssl)
+# Not all platforms include /usr/local in default search path
+CFLAGS  += -I/usr/local/include
+LDFLAGS += -L/usr/local/lib
+# Build shared libraries
+CFLAGS  += -fPIC
+endif
+
 ########################################################################
 #
 # Pretty-printing utilities
@@ -143,14 +151,14 @@ CRYPTO_ENGINE = $(SRC_PATH)/soter/$(CRYPTO_ENGINE_PATH)
 CFLAGS += -D$(CRYPTO_ENGINE_DEF) -DCRYPTO_ENGINE_PATH=$(CRYPTO_ENGINE_PATH)
 CFLAGS += $(CRYPTO_ENGINE_CFLAGS)
 
-
+ifeq ($(ENGINE),boringssl)
 # Basic compiler flags (lower priority than vendored boringssl)
 # Not all platforms include /usr/local in default search path
 CFLAGS  += -I/usr/local/include
 LDFLAGS += -L/usr/local/lib
 # Build shared libraries
 CFLAGS  += -fPIC
-
+endif
 
 # If we're building for macOS and there's Homebrew installed then prefer
 # Homebrew's OpenSSL instead of the system one by default.