meta-ibm: p10bmc: fix inconsistency in string

bitbake uses double-quotes for strings.  Switch the stray single-quoted
string to use double-quote.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Icbc9295ce2468ed7646ab0039b9bc5480a43e6fa
diff --git a/meta-ibm/conf/machine/p10bmc.conf b/meta-ibm/conf/machine/p10bmc.conf
index f11657b..ec03271 100644
--- a/meta-ibm/conf/machine/p10bmc.conf
+++ b/meta-ibm/conf/machine/p10bmc.conf
@@ -26,7 +26,7 @@
 require conf/distro/include/ibm-yaml.inc
 include conf/distro/include/extra-dev-debug-tools.inc
 DISTRO_FEATURES += "ibm-service-account-policy"
-MACHINE_FEATURES += 'phal tpm2'
+MACHINE_FEATURES += "phal tpm2"
 
 SERIAL_CONSOLES = "115200;ttyS4"