Only use -mtune=generic on intel-based architectures

Signed-off-by: falkTX <falktx@falktx.com>

Makefile.base.mk

@@ -129,10 +129,10 @@ endif
 # Set build and link flags
 
 BASE_FLAGS = -Wall -Wextra -pipe -MD -MP
-BASE_OPTS  = -O3 -ffast-math -mtune=generic -fdata-sections -ffunction-sections
+BASE_OPTS  = -O3 -ffast-math -fdata-sections -ffunction-sections
 
 ifeq ($(CPU_I386_OR_X86_64),true)
-BASE_OPTS += -msse -msse2
+BASE_OPTS += -mtune=generic -msse -msse2
 endif
 
 ifeq ($(CPU_ARM),true)