arm-bsp/corstone1000: white space clean-up

Seeing the following warnings:
WARNING: /builds/jonmason00/meta-arm/work/build/../../meta-arm-bsp/conf/machine/include/corstone1000.inc:72 has a lack of whitespace around the assignment: 'SMMGW_AUTH_VAR="1"'
WARNING: /builds/jonmason00/meta-arm/work/build/../../meta-arm-bsp/conf/machine/include/corstone1000.inc:74 has a lack of whitespace around the assignment: 'SMMGW_INTERNAL_CRYPTO="1"'

Add the necessary white space to address the issue.

Signed-off-by: Jon Mason <jon.mason@arm.com>

meta-arm-bsp/conf/machine/include/corstone1000.inc

@@ -69,6 +69,6 @@ ARM_SYSTEMREADY_ACS_CONSOLE ?= "default"
 IMAGE_ROOTFS_EXTRA_ARGS += "--extra-space ${@${IMAGE_ROOTFS_EXTRA_SPACE}}K"
 
 # Enable Authenticated variable support in SmmGW
-SMMGW_AUTH_VAR="1"
+SMMGW_AUTH_VAR = "1"
 # Use MbedTLS build into SmmGW for authentication related crypto operations.
-SMMGW_INTERNAL_CRYPTO="1"
+SMMGW_INTERNAL_CRYPTO = "1"