Build.config : Update RSA to 4096

Update RSA to 4096 for dm-verity.

Change-Id: I8bf2e2870c160e47f482f7e63abf732b08f9e278
Signed-off-by: Abhilasha Manna <quic_amanna@quicinc.com>

build.config.sxr.common

@@ -14,7 +14,7 @@ append_cmd POST_DEFCONFIG_CMDS 'update_signing_keys_config'
 
 function update_signing_keys_config() {
 	if test -f "${OPENSSL_DIR}"; then
-		${OPENSSL_DIR} req -new -nodes -utf8 -newkey rsa:1024 -days 36500 \
+		${OPENSSL_DIR} req -new -nodes -utf8 -newkey rsa:4096 -days 36500 \
 		             -batch -x509 -config ${KERNEL_DIR}/certs/qcom_x509.genkey \
 		             -outform PEM -out ${OUT_DIR}/verity_cert.pem -keyout ${OUT_DIR}/verity_key.pem