newlib: Use mcmodel=medany for RISCV64

It was previously discovered that mcmodel=medany should be used for RISCV64,
however this was only being set for the applications themselves, but not for
newlib, this meant that we ended up with C library that used a code model and
an application that used another one which is not something we want.

Pass mcmodel=medany when building newlib for RISCV64 as well.

Also, s/CFLAGS/TARGET_CFLAGS to standarize across recipes, the variable
expansion provides no functional difference at this point.

(From OE-Core rev: 3ed0a2fab5dbc37dd352ead8846da6aae5de5c20)

Signed-off-by: Alejandro Enedino Hernandez Samaniego <alejandro@enedino.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes-recipe/baremetal-image.bbclass

@@ -103,7 +103,7 @@ QB_OPT_APPEND:append:qemuriscv32 = " -bios none"
 # since medlow can only access addresses below 0x80000000 and RAM
 # starts at 0x80000000 on RISC-V 64
 # Keep RISC-V 32 using -mcmodel=medlow (symbols lie between -2GB:2GB)
-CFLAGS:append:qemuriscv64 = " -mcmodel=medany"
+TARGET_CFLAGS:append:qemuriscv64 = " -mcmodel=medany"
 
 
 ## Emulate image.bbclass

meta/recipes-core/newlib/newlib.inc

@@ -28,6 +28,14 @@ B = "${WORKDIR}/build"
 ## disable stdlib
 TARGET_CC_ARCH:append = " -nostdlib"
 
+# Both the C library and the application should share the same mcmodel.
+# Use the medium-any code model for the RISC-V 64 bit implementation,
+# since medlow can only access addresses below 0x80000000 and RAM
+# starts at 0x80000000 on RISC-V 64
+# Keep RISC-V 32 using -mcmodel=medlow (symbols lie between -2GB:2GB)
+TARGET_CFLAGS:append:qemuriscv64 = " -mcmodel=medany"
+
+
 EXTRA_OECONF = " \
                 --build=${BUILD_SYS}  \
                 --target=${TARGET_SYS} \