Convert CONFIG_REMAKE_ELF to Kconfig

This converts the following to Kconfig:
   CONFIG_REMAKE_ELF

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
diff --git a/configs/rzg2_beacon_defconfig b/configs/rzg2_beacon_defconfig
index 1ae12b1..e6a0d68 100644
--- a/configs/rzg2_beacon_defconfig
+++ b/configs/rzg2_beacon_defconfig
@@ -10,6 +10,7 @@
 CONFIG_TARGET_BEACON_RZG2M=y
 # CONFIG_SPL is not set
 CONFIG_LTO=y
+CONFIG_REMAKE_ELF=y
 CONFIG_SYS_LOAD_ADDR=0x58000000
 CONFIG_FIT=y
 CONFIG_SUPPORT_RAW_INITRD=y