env: Rework ENV_IS_EMBEDDED and related logic slightly

- Drop CONFIG_BUILD_ENVCRC as this is never set directly but instead
  means ENV_IS_EMBEDDED, so reference that in code and rename the Makefile
  usage to BUILD_ENVCRC.
- Remove extra-$(CONFIG_ENV_IS_EMBEDDED) line as it could never be true,
  and likely why there is an extra- line for CONFIG_ENV_IS_IN_FLASH (the
  only use case today of embedded environments).
- With these slight changes we can then see that using the calculated
  symbol of ENV_IS_EMBEDDED is the right thing to use in any code which
  needs to know this situation and can remove CONFIG_ENV_IS_EMBEDDED
  entirely.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/tools/Makefile b/tools/Makefile
index 80bc62b..edfa409 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -36,21 +36,20 @@
 subdir-$(HOST_TOOLS_ALL) += gdb
 
 # Merge all the different vars for envcrc into one
-ENVCRC-$(CONFIG_ENV_IS_EMBEDDED) = y
 ENVCRC-$(CONFIG_ENV_IS_IN_EEPROM) = y
 ENVCRC-$(CONFIG_ENV_IS_IN_FLASH) = y
 ENVCRC-$(CONFIG_ENV_IS_IN_ONENAND) = y
 ENVCRC-$(CONFIG_ENV_IS_IN_NAND) = y
 ENVCRC-$(CONFIG_ENV_IS_IN_NVRAM) = y
 ENVCRC-$(CONFIG_ENV_IS_IN_SPI_FLASH) = y
-CONFIG_BUILD_ENVCRC ?= $(ENVCRC-y)
+BUILD_ENVCRC ?= $(ENVCRC-y)
 
 hostprogs-$(CONFIG_SPL_GENERATE_ATMEL_PMECC_HEADER) += atmel_pmecc_params
 
 hostprogs-$(CONFIG_VIDEO_LOGO) += bmp_logo
 HOSTCFLAGS_bmp_logo.o := -pedantic
 
-hostprogs-$(CONFIG_BUILD_ENVCRC) += envcrc
+hostprogs-$(BUILD_ENVCRC) += envcrc
 envcrc-objs := envcrc.o lib/crc32.o env/embedded.o lib/sha1.o
 
 hostprogs-$(CONFIG_CMD_NET) += gen_eth_addr
diff --git a/tools/envcrc.c b/tools/envcrc.c
index a021c78..550f310 100644
--- a/tools/envcrc.c
+++ b/tools/envcrc.c
@@ -40,10 +40,6 @@
 # endif
 #endif	/* CONFIG_ENV_IS_IN_FLASH */
 
-#if defined(ENV_IS_EMBEDDED) && !defined(CONFIG_BUILD_ENVCRC)
-# define CONFIG_BUILD_ENVCRC
-#endif
-
 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
 # define ENV_HEADER_SIZE	(sizeof(uint32_t) + 1)
 #else
@@ -53,17 +49,17 @@
 #define ENV_SIZE (CONFIG_ENV_SIZE - ENV_HEADER_SIZE)
 
 
-#ifdef CONFIG_BUILD_ENVCRC
+#ifdef ENV_IS_EMBEDDED
 # include <env_internal.h>
 extern unsigned int env_size;
 extern env_t embedded_environment;
-#endif	/* CONFIG_BUILD_ENVCRC */
+#endif	/* ENV_IS_EMBEDDED */
 
 extern uint32_t crc32(uint32_t, const unsigned char *, unsigned int);
 
 int main (int argc, char **argv)
 {
-#ifdef CONFIG_BUILD_ENVCRC
+#ifdef ENV_IS_EMBEDDED
 	unsigned char pad = 0x00;
 	uint32_t crc;
 	unsigned char *envptr = (unsigned char *)&embedded_environment,