mb/emulation/qemu-q35: Move QEMU specific macros to "q35.h"

As `qemu-q35/memmap.c` includes `qemu-q35/q35.h`, move macros into q35.h
file.

Change-Id: I0bf13def8bc4510053f6bb44e043bbcb0b958b01
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83407
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>

src/mainboard/emulation/qemu-q35/memmap.c

@@ -34,10 +34,6 @@ void mainboard_machine_check(void)
 		die("You must run qemu for machine Q35 (-M q35)");
 }
 
-/* QEMU-specific register */
-#define EXT_TSEG_MBYTES	0x50
-#define C_BASE_SEG	((0 << 2) | (1 << 1) | (0 << 0))
-
 /* Decodes TSEG region size to bytes. */
 static size_t decode_tseg_size(u8 esmramc)
 {

src/mainboard/emulation/qemu-q35/q35.h

@@ -8,6 +8,9 @@
 
 #define HOST_BRIDGE	PCI_DEV(0, 0, 0)
 
+#define EXT_TSEG_MBYTES		0x50
+#define C_BASE_SEG		((0 << 2) | (1 << 1) | (0 << 0))
+
 #define D0F0_PCIEXBAR_LO	0x60
 #define D0F0_PCIEXBAR_HI	0x64