dm: core: Require users of devres to include the header

At present devres.h is included in all files that include dm.h but few
make use of it. Also this pulls in linux/compat which adds several more
headers. Drop the automatic inclusion and require files to include devres
themselves. This provides a good indication of which files use devres.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index 31f6cfe..1fcbc35 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -13,6 +13,7 @@
 #include <reset.h>
 #include <serial.h>
 #include <watchdog.h>
+#include <linux/err.h>
 #include <linux/types.h>
 #include <asm/io.h>
 
diff --git a/drivers/serial/serial_mtk.c b/drivers/serial/serial_mtk.c
index 18530a4..e63f230 100644
--- a/drivers/serial/serial_mtk.c
+++ b/drivers/serial/serial_mtk.c
@@ -15,6 +15,7 @@
 #include <watchdog.h>
 #include <asm/io.h>
 #include <asm/types.h>
+#include <linux/err.h>
 
 struct mtk_serial_regs {
 	u32 rbr;
@@ -454,4 +455,4 @@
 
 DEBUG_UART_FUNCS
 
-#endif
\ No newline at end of file
+#endif
diff --git a/drivers/serial/serial_omap.c b/drivers/serial/serial_omap.c
index a31d737..4d4d919 100644
--- a/drivers/serial/serial_omap.c
+++ b/drivers/serial/serial_omap.c
@@ -12,6 +12,7 @@
 #include <ns16550.h>
 #include <serial.h>
 #include <clk.h>
+#include <linux/err.h>
 
 #ifndef CONFIG_SYS_NS16550_CLK
 #define CONFIG_SYS_NS16550_CLK  0
diff --git a/drivers/serial/serial_sifive.c b/drivers/serial/serial_sifive.c
index c142ccd..5a02f0c 100644
--- a/drivers/serial/serial_sifive.c
+++ b/drivers/serial/serial_sifive.c
@@ -13,6 +13,7 @@
 #include <asm/io.h>
 #include <linux/compiler.h>
 #include <serial.h>
+#include <linux/err.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
diff --git a/drivers/serial/serial_zynq.c b/drivers/serial/serial_zynq.c
index 7e486a6..c073759 100644
--- a/drivers/serial/serial_zynq.c
+++ b/drivers/serial/serial_zynq.c
@@ -14,6 +14,7 @@
 #include <asm/io.h>
 #include <linux/compiler.h>
 #include <serial.h>
+#include <linux/err.h>
 
 DECLARE_GLOBAL_DATA_PTR;