boot: Move OS options into /boot

These options belong in boot/Kconfig since they are not related to
commands. Move them and adjust them to depend on CONFIG_BOOT

Signed-off-by: Simon Glass <sjg@chromium.org>

cmd/Kconfig

@@ -367,48 +367,6 @@ config CMD_BOOTI
 	help
 	  Boot an AArch64 Linux Kernel image from memory.
 
-config BOOTM_LINUX
-	bool "Support booting Linux OS images"
-	depends on BOOT
-	default y
-	help
-	  Support booting the Linux kernel directly via a command such as bootm
-	  or booti or bootz.
-
-config BOOTM_NETBSD
-	bool "Support booting NetBSD (non-EFI) loader images"
-	depends on CMD_BOOTM
-	default y
-	help
-	  Support booting NetBSD via the bootm command.
-
-config BOOTM_OPENRTOS
-	bool "Support booting OPENRTOS / FreeRTOS images"
-	depends on CMD_BOOTM
-	help
-	  Support booting OPENRTOS / FreeRTOS via the bootm command.
-
-config BOOTM_OSE
-	bool "Support booting Enea OSE images"
-	depends on (ARM && (ARM64 || CPU_V7A || CPU_V7R) || SANDBOX || PPC || X86)
-	depends on CMD_BOOTM
-	help
-	  Support booting Enea OSE images via the bootm command.
-
-config BOOTM_PLAN9
-	bool "Support booting Plan9 OS images"
-	depends on CMD_BOOTM
-	default y
-	help
-	  Support booting Plan9 images via the bootm command.
-
-config BOOTM_RTEMS
-	bool "Support booting RTEMS OS images"
-	depends on CMD_BOOTM
-	default y
-	help
-	  Support booting RTEMS images via the bootm command.
-
 config CMD_SEAMA
 	bool "Support read SEAMA NAND images"
 	depends on MTD_RAW_NAND
@@ -432,13 +390,6 @@ config CMD_VBE
 	  is used to boot. Updating the parameters is not currently
 	  supported.
 
-config BOOTM_VXWORKS
-	bool "Support booting VxWorks OS images"
-	depends on CMD_BOOTM
-	default y
-	help
-	  Support booting VxWorks images via the bootm command.
-
 config CMD_BOOTEFI
 	bool "bootefi"
 	depends on EFI_LOADER