treewide: Convert CONFIG_HOSTNAME to a string option

CONFIG_HOSTNAME is defined as a "plain" preprocessor string, but every
use is couched by __stringify(...).

Hence, convert it to a proper string option.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/include/configs/km_kirkwood.h b/include/configs/km_kirkwood.h
index 0d78cfa..15e4b46 100644
--- a/include/configs/km_kirkwood.h
+++ b/include/configs/km_kirkwood.h
@@ -23,13 +23,13 @@
 
 /* KM_KIRKWOOD */
 #if defined(CONFIG_KM_KIRKWOOD)
-#define CONFIG_HOSTNAME			km_kirkwood
+#define CONFIG_HOSTNAME			"km_kirkwood"
 #define CONFIG_KM_DISABLE_PCIE
 #define CONFIG_KM_IVM_BUS		1	/* I2C2 (Mux-Port 1)*/
 
 /* KM_KIRKWOOD_PCI */
 #elif defined(CONFIG_KM_KIRKWOOD_PCI)
-#define CONFIG_HOSTNAME			km_kirkwood_pci
+#define CONFIG_HOSTNAME			"km_kirkwood_pci"
 #define CONFIG_KM_IVM_BUS		1	/* I2C2 (Mux-Port 1)*/
 #define CONFIG_KM_FPGA_CONFIG
 #define CONFIG_KM_UBI_PART_BOOT_OPTS		",2048"
@@ -37,7 +37,7 @@
 
 /* KM_KIRKWOOD_128M16 */
 #elif defined(CONFIG_KM_KIRKWOOD_128M16)
-#define CONFIG_HOSTNAME			km_kirkwood_128m16
+#define CONFIG_HOSTNAME			"km_kirkwood_128m16"
 #undef CONFIG_SYS_KWD_CONFIG
 #define CONFIG_SYS_KWD_CONFIG $(CONFIG_BOARDDIR)/kwbimage_128M16_1.cfg
 #define CONFIG_KM_DISABLE_PCIE
@@ -48,9 +48,9 @@
 #define CONFIG_KM_IVM_BUS		1	/* I2C2 (Mux-Port 1)*/
 
 # if defined(CONFIG_KM_NUSA)
-#define CONFIG_HOSTNAME			kmnusa
+#define CONFIG_HOSTNAME			"kmnusa"
 # elif defined(CONFIG_KM_SUGP1)
-#define CONFIG_HOSTNAME			kmsugp1
+#define CONFIG_HOSTNAME			"kmsugp1"
 #define KM_PCIE_RESET_MPP7
 #endif
 
@@ -64,7 +64,7 @@
 
 /* KM_MGCOGE3UN */
 #elif defined(CONFIG_KM_MGCOGE3UN)
-#define CONFIG_HOSTNAME			mgcoge3un
+#define CONFIG_HOSTNAME			"mgcoge3un"
 #define CONFIG_KM_IVM_BUS		1	/* I2C2 (Mux-Port 1)*/
 #undef CONFIG_SYS_KWD_CONFIG
 #define CONFIG_SYS_KWD_CONFIG $(CONFIG_BOARDDIR)/kwbimage-memphis.cfg
@@ -80,20 +80,20 @@
 #define CONFIG_SYS_KWD_CONFIG $(CONFIG_BOARDDIR)/kwbimage_256M8_1.cfg
 #define CONFIG_KM_ENV_IS_IN_SPI_NOR
 #define CONFIG_PIGGY_MAC_ADRESS_OFFSET	3
-#define CONFIG_HOSTNAME			kmcoge5un
+#define CONFIG_HOSTNAME			"kmcoge5un"
 #define CONFIG_KM_DISABLE_PCIE
 #define CONFIG_KM_PIGGY4_88E6352
 
 /* KM_PORTL2 */
 #elif defined(CONFIG_KM_PORTL2)
-#define CONFIG_HOSTNAME			portl2
+#define CONFIG_HOSTNAME			"portl2"
 #define CONFIG_KM_IVM_BUS		1	/* I2C2 (Mux-Port 1)*/
 #define CONFIG_KM_PIGGY4_88E6061
 
 /* KM_SUV31 */
 #elif defined(CONFIG_KM_SUV31)
 #define CONFIG_KM_IVM_BUS		1	/* I2C2 (Mux-Port 1)*/
-#define CONFIG_HOSTNAME			kmsuv31
+#define CONFIG_HOSTNAME			"kmsuv31"
 #undef CONFIG_SYS_KWD_CONFIG
 #define CONFIG_SYS_KWD_CONFIG $(CONFIG_BOARDDIR)/kwbimage_128M16_1.cfg
 #define CONFIG_KM_ENV_IS_IN_SPI_NOR