drivers: regulator: Drop rpm_smd_regulator_driver_init export

WARNING: vmlinux.o(___ksymtab+rpm_smd_regulator_driver_init+0x0):
  Section mismatch in reference from the variable
  __ksymtab_rpm_smd_regulator_driver_init to the function
  .init.text:rpm_smd_regulator_driver_init()
The symbol rpm_smd_regulator_driver_init is exported and annotated
  __init
Fix this by removing the __init annotation of
  rpm_smd_regulator_driver_init or drop the export.

FATAL: modpost: Section mismatches detected.

drivers/regulator/rpm-smd-regulator.c

@@ -2061,7 +2061,6 @@ int __init rpm_smd_regulator_driver_init(void)
 
 	return platform_driver_register(&rpm_vreg_resource_driver);
 }
-EXPORT_SYMBOL(rpm_smd_regulator_driver_init);
 
 static void __exit rpm_vreg_exit(void)
 {